UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

Filed by the Registrant  ☒                             Filed by a Party other than the Registrant  ☐

Check the appropriate box:

GLADSTONE CAPITAL CORPORATION

(Name of Registrant as Specified In Its Charter)

Not Applicable

(Name of Person(s) Filing Proxy Statement, if Other Than the Registrant)

Payment of Filing Fee (Check the appropriate box)

Preliminary Copy

GLADSTONE CAPITAL CORPORATION

1521 Westbranch Drive, Suite 100, McLean, Virginia 22102

NOTICE OF SPECIALANNUAL MEETING OF STOCKHOLDERS

TO BE HELD ON December 11, 2023FEBRUARY 1, 2024

To the Stockholders of Gladstone Capital Corporation:

Notice Is Hereby Given that a Specialthe 2024 Annual Meeting of Stockholders (the “Special“Annual Meeting”) of Gladstone Capital Corporation, a Maryland corporation, (the “Company”), will be held on December 11, 2023,Thursday, February 1, 2024, at 10:3011:00 a.m. Eastern Time. The SpecialAnnual Meeting will be a completely “virtual meeting.” You will be able to attend the meeting, as well as vote and submit your questions during the live webcast of the meeting, by visiting www.virtualshareholdermeeting.com/GLAD2023SMGLAD2024 and entering the company number and control number included on your proxy card or in the instructions that accompany your proxy materials.

At the SpecialAnnual Meeting, you will be asked to consider and vote upon the following proposal:proposals:

The foregoing itemitems of business isare more fully described in the Proxy Statement accompanying this Notice.

We intend to mail these materials on or about October 26,December 15, 2023 to all stockholders of record entitled to vote at the SpecialAnnual Meeting. Our Board of Directors has fixed the close of business on October 18,Friday, December 1, 2023 as the record date for the determination of stockholders entitled to notice of and to vote at the SpecialAnnual Meeting and at any adjournment or postponement thereof.

As further described in the Proxy Statement accompanying this Notice, based on a consideration of all the factors in their totality, our Board of Directors, including each of the independent directors, unanimously determined that the New Advisory Agreement, including the compensation payable under the agreement, was fair and reasonable to the Company. Our Board of Directors, including each of the independent directors, therefore unanimously determined that the approval of the New Advisory Agreement was in the best interests of the Company and its stockholders.

There are no changes to the terms, including the fee structure and services to be provided, of the advisory agreement between the Company and the Adviser currently in effect (the “Original Advisory Agreement”) in the New Advisory Agreement, other than the date and term of the New Advisory Agreement as compared to the Original Advisory Agreement. In addition to there being no changes to the fee structure, no other fees or expenses currently paid by the Company will change as a result of entry into the New Advisory Agreement.

McLean, Virginia

October 26,December 15, 2023

ALL OF OUR STOCKHOLDERS ARE CORDIALLY INVITED TO ATTEND THE SPECIALANNUAL MEETING VIA WEBCAST. WHETHER OR NOT YOU PLAN TO ATTEND THE SPECIALANNUAL MEETING, YOU ARE URGED TO COMPLETE, DATE, SIGN AND RETURN THE ENCLOSED PROXY CARD AS PROMPTLY AS POSSIBLE, SUBMIT YOUR PROXY ELECTRONICALLY VIA THE INTERNET OR VOTE BY PROXY OVER THE TELEPHONE, AS INSTRUCTED IN THESE MATERIALS. SUBMITTING YOUR PROXY OR VOTING INSTRUCTIONS PROMPTLY WILL ASSIST US IN REDUCING THE EXPENSES OF ADDITIONAL PROXY SOLICITATION, BUT IT WILL NOT AFFECT YOUR RIGHT TO VOTE IF YOU ATTEND THE SPECIALANNUAL MEETING (AND, IF YOU ARE NOT A STOCKHOLDER OF RECORD, YOU HAVE OBTAINED A LEGAL PROXY FROM THE BANK, BROKER, TRUSTEE OR OTHER NOMINEE THAT HOLDS YOUR SHARES GIVING YOU THE RIGHT TO VOTE THE SHARES AT THE SPECIALANNUAL MEETING).

TABLE OF CONTENTS

Preliminary Copy

GLADSTONE CAPITAL CORPORATION

1521 Westbranch Drive, Suite 100, McLean, Virginia 22102

PROXY STATEMENT

FOR THE SPECIAL2024 ANNUAL MEETING OF STOCKHOLDERS

To Be Held On December 11, 2023February 1, 2024

QUESTIONS AND ANSWERS ABOUT THIS PROXY MATERIAL AND VOTING

Why am I receiving these materials?

We have sent you this Proxy Statement and the enclosed proxy card because the board of directors (the “Board”) of Gladstone Capital Corporation (“we,” “us,” or the “Company”) is soliciting your proxy to vote at the special meeting2024 Annual Meeting of the Company’s stockholders to be held on December 11, 2023Stockholders (the “meeting” or “special“annual meeting”), including adjournments or postponements thereof, if any. You are invited to attend the specialannual meeting to vote on the proposalproposals described in this Proxy Statement, which meeting will take place through a live webcast by visiting www.virtualshareholdermeeting.com/GLAD2023SMGLAD2024. However, you do not need to attend the meeting through the webcast to vote your shares. Instead, you may simply complete, sign and return the enclosed proxy card, or follow the instructions below to vote by proxy over the telephone or through the Internet prior to the specialannual meeting.

We intend to mail these materials on or about October 26,December 15, 2023 to all stockholders of record entitled to vote at the specialannual meeting.

YOUR VOTE IS IMPORTANT.

WHETHER OR NOT YOU PLAN TO ATTEND THE MEETING, PLEASE PROMPTLY AUTHORIZE A PROXY TO VOTE YOUR SHARES EITHER BY MAIL, BY TELEPHONE, OR THROUGH THE INTERNET.

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE SPECIALANNUAL MEETING TO BE HELD ON DECEMBER 11, 2023:FEBRUARY 1, 2024:

The Notice of SpecialAnnual Meeting, and this Proxy Statement and our Annual Report on Form 10-K for the fiscal year ended September 30, 2023 are available at the following Internet address: www.proxyvote.com.

How can I attend the specialannual meeting?

The meeting will be held on December 11, 2023,Thursday, February 1, 2024, at 10:3011:00 a.m., Eastern Time, virtually, in a live webcast on the website www.virtualshareholdermeeting.com/GLAD2023SMGLAD2024 where you will be able to vote your shares during the meeting and submit any questions. You will need to enter the company number and the control number included on your proxy card or in the instructions that accompany your proxy materials to enter the meeting. If you experience technical difficulties in attending the meeting virtually, please dial 844-986-0822 (US) or 303-562-9302 (International) for assistance.

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Who can vote at the specialannual meeting?

Only holders of record of our common stock, $0.001 par value per share (the “common stock”), at the close of business on October 18,December 1, 2023 will be entitled to vote at the specialannual meeting. OnAs of the close of business on the record date, there were 43,508,897 [—] shares of common stock outstanding and entitled to vote.

Stockholder of Record: Shares Registered in Your Name

If at the close of business on October 18,December 1, 2023, your shares were registered directly in your name with our transfer agent, Computershare, Inc., then you are a stockholder of record. As a stockholder of record, you may vote at the meeting or vote by proxy. Whether or not you plan to attend the meeting, we urge you to fill out and return the enclosed proxy card or vote by proxy over the telephone or through the Internet as instructed below to ensure your vote is counted.

Beneficial Owner: Shares Held in the Name of a Broker, Bank, Nominee, or other Similar Organization

If at the close of business on October 18,December 1, 2023, your shares were held, not in your name, but in an account at a brokerage firm, bank, dealer, or other similar organization or nominee (collectively, a “Brokerage Firm”), then you are the beneficial owner of shares held in “street name” and these proxy materials are being forwarded to you by that Brokerage Firm because the Brokerage Firm holding your account or its nominee is considered to be the stockholder of record for purposes of voting at the specialannual meeting. As a beneficial owner, you have the right to direct your Brokerage Firm regarding how to vote the shares in your account. You are also invited to attend the specialannual meeting via live webcast on the website: www.virtualshareholdermeeting.com/GLAD2023SMGLAD2024. However, since you are not the stockholder of record, you may not vote your shares at the meeting unless you request and obtain a valid proxy from your Brokerage Firm.

What am I voting on?

There is one matterare three matters scheduled for a vote:

Has theHow do I vote?

For Proposal 1, you may either vote “FOR ALL” nominees for directors of our Board, considered whether the New Advisory Agreement is in the best interests of the Company and its stockholders?

As further described below under “Approval of the New Advisory Agreement - Recommendation of the BoardWITHHOLD ALL,”, based on a consideration of all the factors in their totality, the Board, including each of the independent directors, unanimously determined meaning that the New Advisory Agreement, including the compensation payable under the agreement, was fair and reasonable to the Company. The Board, including each of the independent directors, therefore unanimously determined that the approval of the New Advisory Agreement was in the best interests of the Company and its stockholders.you do not vote for any nominee for director, or “FORALL

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Are thereEXCEPT,” meaning that you vote for all nominees for director except any material changes between Original Advisory Agreementnominee you specify. For each of Proposal 2 and the New Advisory Agreement?

As further described below under “Approval of the New Advisory Agreement - Background”, there are no changes to the terms, including the fee structure and services to be provided, of the currently existing investment advisory agreement between the Company and the Adviser (the “Original Advisory Agreement”) in the New Advisory Agreement, other than the date and term of the New Advisory Agreement as compared to the Original Advisory Agreement. In addition to there being no changes to the fee structure, no other fees or expenses currently paid by the Company will change as a result of entry into the New Advisory Agreement.

Will there be any changes to the Company’s principal investment objective, investment strategies, fundamental investment restrictions or principal risks as a result of entry into the Voting Trust Agreement or New Advisory Agreement?

There will be no changes to the Company’s principal investment objective, investment strategies, fundamental investment restrictions or principal risks as a result of entry into the Voting Trust Agreement (as defined below) or the New Advisory Agreement.

How do I vote?

For the Proposal 3, you may vote “FOR” or “AGAINST” or “ABSTAIN” from voting. The procedures for voting are as follows:

Stockholder of Record: Shares Registered in Your Name

If you are a stockholder of record, you may vote at the specialannual meeting, vote by proxy using the enclosed proxy card and return envelope, or vote by proxy over the telephone or through the Internet. Whether or not you plan to attend the meeting, we urge you to vote by proxy to ensure your vote is counted. You may still attend the meeting via webcast and vote in person, even if you have already voted by proxy.

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How are votes counted?

Votes will be counted by the inspectors of election appointed for the specialannual meeting, who will separately count “FORALL,” “WITHHOLD ALL,” and “FOR ALL EXCEPT” votes for the election of directors and, with respect to proposals other than the election of directors, “FOR,” “AGAINST” and “ABSTAIN” votes. The effects of abstentions and broker non-voteson the Proposaleach proposal are described below under the question “How many votes are needed to approve the Proposal?each proposal?” We expect that Nicole Schaltenbrand, our chief financial officer and treasurer, and Michael LiCalsi, our general counsel and secretary, will be appointed as the inspectors of election.

How many votes are needed to approve each proposal?

Vote Required

Proposal 1—Election of Directors. Each of Walter H. Wilkinson and Paula Novara must be elected by a plurality of votes cast at the Proposal?

Approvalannual meeting by holders of our outstanding common stock. Only votes “FOR” a particular nominee for director will affect the outcome of the New Advisory Agreement requireselection of such nominee. Under a plurality vote standard, the nominees that receive the highest number of votes cast will be elected regardless of whether they receive a majority of votes cast. Broker non-votes and withheld votes will not be counted as votes cast with respect to the proposal and will have no effect on the outcome of such proposal; however, they will be counted towards the quorum requirement.

Proposal 2—Ratification of our independent registered public accounting firm. The affirmative vote of a “majoritymajority of the outstanding voting securities”votes cast by holders of common stock at the Company. Underannual meeting is required to ratify the Investment Company ActAudit Committee’s selection of 1940,PwC as amended (the “1940 Act”), a “majorityour independent registered public accounting firm for the fiscal year ending September 30, 2024. Abstentions will not be counted as votes cast for this proposal and will have no effect on the outcome of outstanding voting securities” meanssuch proposal; however, they will be counted towards the quorum requirement.

Proposal 3—Approval of an amendment to our charter to increase the number of authorized shares of common stock. The affirmative vote of the lesser of (a) 67% or moretwo-thirds of the sharesvotes entitled to be cast by holders of the Company’sall common stock present or represented by proxyentitled to vote at the specialannual meeting ifis required to approve an amendment to our charter to increase the holdersnumber of more than 50% of the outstanding shares of the Company’s common stock are present or represented by proxy at the special meeting or (b) more than 50% of the outstandingauthorized shares of common stock of the Company.stock. Abstentions will have the effect of a vote “AGAINST” this proposal. If the Proposal is approved by the Company’s stockholders, the New Advisory Agreementproposal; however, they will be entered into oncounted towards the Effective Date (as defined below) by the relevant parties. If the Proposal is not approved by the Company’s stockholders, the Board will consider alternatives for the Company, including seeking subsequent approval of a different new investment advisory agreement by the Company’s stockholders.quorum requirement.

What are “broker non-votes?”non-votes”?

Broker non-votes occur when a beneficial owner of shares held in “street name” does not give instructions to the broker or nominee holding the shares as to how to vote on matters deemed “non-routine.” Generally, if shares are held in street name, the beneficial owner of the shares is entitled to

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Because it is a non-routine proposal, your Brokerage Firmbroker, bank or other agent is not entitled to vote your shares without your instructions with respect to the approvalProposal 1 (election of directors). However, Proposal 2 (ratification of the New Advisory Agreement. Thus, if you do notappointment of PwC) and Proposal 3 (charter amendment) are routine proposals and your broker, bank or other agent may vote or give your Brokerage Firm specific instructions on how to vote for you, your Brokerage Firm cannot voteshares with respect to the Proposal 2 and your shares willProposal 3 even if it does not be treated as present for quorum purposes.receive instructions from you.

What is the quorum requirement?

A quorum of stockholders is necessary to hold a valid meeting. A quorum will be present if a majority of all of ourthe outstanding shares of our common stock entitled to vote are represented by stockholders present at the meeting or by proxy. OnAs of the close of business on the record date there were 43,508,897[—] shares of common stock outstanding and entitled to vote. Thus, 21,754,449 [—] shares must be represented by stockholders present at the meeting or by proxy to have a quorum.

Your shares will be counted towards the quorum only if you submit a valid proxy (or one is submitted on your behalf by your Brokerage Firm or other nominee) or if you vote in person at the meeting. AbstentionsWithhold votes, abstentions and broker non-votes will be counted towards the quorum requirement. If a broker or other recordholder attempts to give us any proxy authority with respect to uninstructed shares, we will not consider those shares present for quorum or any other purposes. If there is no quorum, the stockholders present and entitled to vote at the meeting may adjourn the meeting to another date.

What if I return a proxy card but do not make specific choices?

If you return a signed and dated proxy card, or otherwise vote by proxy without making any voting selections, your shares will be voted “FOR ALL” the Proposal.nominees for director in Proposal 1, “FOR” Proposal 2 and “FOR” Proposal 3. If any other matter is properly presented at the meeting, your proxy holder (one of the individuals named on the enclosed proxy card) will vote your shares using his or her best judgment.discretion.

Can I change my vote after submitting my proxy?

Yes. You can revoke your proxy at any time before the final vote at the meeting. If you wish to revoke your proxy after 11:59 p.m. Eastern Time on December 10, 2023,January 31, 2024, you may only do so at the specialannual meeting. If you are the record holder of your shares, you may revoke your proxy in any one of the following ways:

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What does it mean if I receive more than one set of proxy materials?

If you receive more than one set of proxy materials, your shares may be registered in more than one name or in different accounts at your Brokerage Firm(s). Please follow the voting instructions on the proxy cards in each set of the proxy materials to ensure that all of your shares are voted.

How can I find out the results of the voting at the specialannual meeting?

Preliminary voting results will be announced at the specialannual meeting. Final voting results will be published in a Current Report on Form 8-K that we willexpect to file with the U.S. Securities and Exchange Commission (“SEC”) within four business days after the specialannual meeting. If final voting results are not available to us to timely file a Form 8-K, we intend to file a Form 8-K to publish preliminary results and, within four business days after the final results are known to us, file an additional Form 8-K to publish the final results.

When are stockholder proposals due for next year’s annual meeting?

We will consider for inclusion in our proxy materials for the 2025 annual meeting proposals that we receive no later than August 17, 2024 and that comply with all applicable requirements of Rule 14a-8 promulgated under the Securities Exchange Act of 1934, as amended (the “1934 Act”), and our bylaws, as amended (“Bylaws”). Stockholders must submit their proposals to our secretary at 1521 Westbranch Drive, Suite 100, McLean, Virginia 22102.

In addition, any stockholder who wishes to propose a nominee to our Board or propose any other business to be considered by the stockholders (other than a stockholder proposal to be included in our proxy materials pursuant to Rule 14a-8 of the 1934 Act) must comply with the advance notice provisions and other requirements of Article II, Section 4(b) of our Bylaws, a copy of which is on file with the SEC and may be obtained without charge from our secretary upon request.

These notice provisions require that nominations of persons for election to our Board and proposals of business to be considered by the stockholders for the 2025 annual meeting must be made in writing and submitted to our secretary at the address above no earlier than the close of business on November 3, 2024 (90 days before the first anniversary of our 2024 Annual Meeting) and no later than the close of business on December 3, 2024 (60 days before the first anniversary of the 2024 Annual Meeting). You are also advised to review our Bylaws, which contain additional requirements about advance notice of stockholder proposals and director nominations.

Who is paying for this proxy solicitation?

The AdviserGladstone Capital Corporation will bear the cost of solicitation of proxies, including preparation, assembly, printing and mailing of this Proxy Statement, the proxy card and any additional information furnished to stockholders. Copies of solicitation materials will be furnished to banks, brokerage houses, fiduciaries and other custodians holding in their names shares of our common stock beneficially owned by others to forward to such beneficial owners. The Company intends to use the services of Alliance Advisors, LLC (“Alliance”) to aid in the distribution and collection of proxies for an estimated fee of approximately $7,000 plus pass through charges (encompassing standard out-of-pocket expenses incurred by Alliance). Alliance’s fees for distribution and collection of proxies and pass through charges will each be paid by the Adviser and such fees and expenses will not be subject to recoupment. Alliance could contact you by telephone on behalf of the Company and urge you to vote. Alliance will not attempt to influence how you vote your shares, but will only ask that you take the time to cast a vote. The AdviserWe may reimburse persons representing beneficial owners of

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our common stock for their costs of forwarding solicitation materials to such beneficial owners. Original solicitation of proxies by mail may be supplemented by telephone, electronic mail or personal solicitation by directors, officers or other regular employees of the AdviserGladstone Management Corporation, our investment adviser (the “Adviser”), or Gladstone Administration, LLC (the “Administrator”). No additional compensation will be paid to directors, officers or other regular employees for such services. In addition to these written proxy materials, our officers and directors may also solicit proxies in person, by telephone or by other means of communication; however, our officers and directors will not be paid any additional compensation for soliciting proxies. The AdviserWe may also reimburse Brokerage Firms and other agents for the cost of forwarding proxy materials to beneficial owners and obtaining your voting instructions.

What proxy materials are available on the Internet?

The Notice of the SpecialAnnual Meeting, and Proxy Statement areand Annual Report on Form 10-K for the year ended September 30, 2023 is also available at www.proxyvote.com.

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PROPOSAL 1

APPROVALELECTION OF THE NEW ADVISORY AGREEMENTDIRECTORS

Our Board is divided into three classes, with staggered three-year terms. Currently our Board is comprised of seven directors, five of whom are independent.

The Board’s Ethics, Nominating & Corporate Governance Committee (the “Ethics Committee”) nominated two incumbent directors to stand for re-election: Walter H. Wilkinson, an independent director, and Paula Novara, an interested director. Proxies cannot be voted for a greater number of persons than the number of nominees named. If elected at the annual meeting, each nominee would serve until the 2027 annual meeting and until his or her successor is duly elected and qualified, or, if sooner, until his or her death, resignation or removal.

Each director is elected by a plurality of the votes cast at the annual meeting. Shares represented by executed proxies will be voted, if the authority to do so is not withheld, “FOR” the election of the two nominees. In the event that any of the nominees should be unavailable for election as a result of an unexpected occurrence, such shares will be voted for the election of such substitute nominees as management may propose. Each person nominated for election has agreed to serve if elected, and management has no reason to believe that any nominee will be unable to serve.

We are askingencourage all of our directors and nominees for director to attend the Company’s stockholders to approveannual meeting; however, attendance is not required. None of our directors attended the New Advisory Agreement, pursuant to which the Adviser2023 Annual Meeting of Stockholders.

Set forth below is biographical information for each person nominated, each person whose term of office as a director will continue after the annual meeting, each executive officer and certain other officers who are not also directors.

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Nominees for a Three-Year Term to serve asExpire at the investment adviser2027 Annual Meeting of Stockholders

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Directors Continuing in Office Until the Company.2025 Annual Meeting of Stockholders

Background

The Adviser has provided investment advisory services to the Company since its inception. Subject to the oversight of the Board, the Adviser serves as the Company’s investment adviser and is responsible for managing the Company’s investments on a day-to-day basis. David Gladstone founded the Adviser and has served as10

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Directors Continuing in Office Until the 2026 Annual Meeting of Stockholders

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Executive Officers and Certain Other Officers Who Are Not Directors

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Qualifications of Director Nominees

When considering whether our director nominee has the experience, qualifications, attributes and skills, taken as a whole, to enable our Board to satisfy its oversight responsibilities effectively in light of our operational and organizational structure, the Ethics Committee and our Board focused primarily on the information discussed in each of the individual backgrounds set forth above and on the following particular attributes:

Qualifications of Incumbent Directors Serving Until the 2025 or 2026 Annual Meeting of Stockholders

When considering whether our directors have the experience, qualifications, attributes and skills, taken as a whole, to enable our Board to satisfy its oversight responsibilities effectively in light of our operational and organizational structure, the Ethics Committee and our Board focused primarily on the information discussed in each of the individual backgrounds set forth above and on the following particular attributes:

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THE BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT STOCKHOLDERS VOTE “FOR” EACH NAMED NOMINEE FOR DIRECTOR IN PROPOSAL 1.

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INFORMATION REGARDING THE BOARD OF DIRECTORS AND CORPORATE

GOVERNANCE

Director Independence

As required under The Nasdaq Stock Market (“Nasdaq”) listing standards, our Board annually determines each director’s independence. The Nasdaq listing standards provide that a director of a business development company is considered to be independent if he or she is not an “interested person” of ours, as defined in Section 2(a)(19) of the 1940 Act. Section 2(a)(19) of the 1940 Act defines an “interested person” to include, among other things, any person who has, or within the last two years had, a material business or professional relationship with us.

Consistent with these considerations, after review of all relevant transactions or relationships between each director, or any of his or her family members, and us, our senior management and our independent registered public accounting firm, our Board has affirmatively determined that the following five directors are independent directors within the meaning of the applicable Nasdaq listing standards: Messrs. Adelgren, Outland, Parker, and Wilkinson and Ms. English. In making this determination, our Board found that none of these directors or nominees for director had a material or other disqualifying relationship with us. Mr. Gladstone, the chairman of our Board and our chief executive officer, and Ms. Novara, Head of Resource Management, are not independent directors by virtue of their positions as officers of the Company and our Adviser and their employment by our Adviser.

Diversity

The following table summarizes certain self-identified characteristics of our directors, in accordance with Nasdaq Listing Rules 5605(f) and 5606. Each term used in the table has the meaning given to it in the rule and related instructions. Our current Nasdaq Board Diversity Matrix is also posted on our website at https://www.gladstonecapital.com/investors/corporate-governance/governance-documents.

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Meetings of the Board of Directors

Our Board met five times during fiscal year 2023. Each Board member attended 75% or more of the Company sinceaggregate of the meetings of our Board and of the committees on which he or she served that were held during fiscal year 2023.

Our independent directors met four times during fiscal year 2023 in regularly scheduled executive sessions, at which only independent directors were present.

Corporate Leadership Structure

Since our inception, Mr. Gladstone has served as chairman of our Board and our chief executive officer. He also served as our president from February 2013 through December 2013. Our Board believes that our chief executive officer is best situated to serve as chairman because he is the director most familiar with our business and industry, and most capable of effectively identifying strategic priorities and leading the discussion and execution of strategy. In addition, Mr. Adelgren, one of our independent directors, serves as the Lead Independent Director. The Lead Independent Director has the responsibility of presiding at all executive sessions of our independent directors, consulting with the chairman and chief executive officer on Board and committee meeting agendas, acting as a liaison between management and the independent directors and facilitating teamwork and communication between the independent directors and management.

Our Board believes the combined role of chairman and chief executive officer, together with an independent Lead Independent Director, is in the best interest of stockholders because it provides the appropriate balance between strategic development and independent oversight of risk management. In coming to this conclusion, our Board considered the importance of having an interested chairperson that is familiar with our day-to-day management activities, our portfolio companies and the operations of our Adviser. Our Board concluded that the combined role enhances, among other things, our Board’s understanding of our investment portfolio, business, finances and risk management efforts. In addition, our Board believes that Mr. Gladstone’s employment by the Adviser better allows for the efficient mobilization of the Adviser’s resources at our Board’s behest and on its inception.behalf.

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Information Regarding Committees of the Board of Directors

The proposalfollowing table identifies our standing committees and their current members and the number of meetings held by each committee during the fiscal year ended September 30, 2023:

Our Board has determined that all members of our Audit Committee are independent (as independence is currently defined in Rules 5605(a)(2) and 5605(c)(2) of the New Advisory AgreementNasdaq listing standards). No member of the Audit Committee received any compensation from us during the last three fiscal years other than directors’ fees. Our Board has unanimously determined all Audit Committee members are financially literate under current Nasdaq rules and approval bythat Messrs. Adelgren, Outland, Parker and Wilkinson and Ms. English each qualifies as an “audit committee financial expert,” as defined in applicable SEC rules. Our Board made a qualitative assessment of the stockholdersmembers’ level of knowledge and experience based on a number of factors, including formal education and experience. Messrs. Parker and Outland and Ms. English also served on the audit committees of Gladstone Commercial Corporation, Gladstone Land Corporation, Gladstone Investment Corporation and Gladstone Acquisition Corporation during the last fiscal year. Each of a similar proposal, the Adviser will enter into a Voting Trust Agreement, among David Gladstone, Lorna Gladstone, Laura Gladstone, Kent Gladstone and Jessica Martin, each as a trustee and collectively, asdirectors resigned from the board of trusteesdirectors of Gladstone Acquisition Corporation effective October 12, 2022. Our board has determined that this simultaneous service did not impair the respective director’s ability to effectively serve on our Audit Committee.

Compensation Committee

The Compensation Committee operates pursuant to a written charter that is available to stockholders in the Investors section of our website at www.gladstonecapital.com. The Compensation Committee conducts periodic reviews of our investment advisory and management agreement with our Adviser (the “Advisory Agreement”) and our administration agreement with our Administrator (the “Administration Agreement”) to evaluate whether the fees paid to our Adviser and our Administrator under the agreements are in the best interests of us and our stockholders. The committee considers in such periodic reviews, among other things, whether the fees paid to our Adviser and our Administrator are reasonable in relation to the nature and quality of services performed and whether the provisions of the voting trust (the “Voting Trust Board”), the AdviserAdvisory and certain stockholdersAdministration Agreements are being satisfactorily performed. The Compensation Committee also reviews with management our Compensation Discussion and Analysis to consider whether to recommend that it be included in proxy statements and other filings.

Our Board has determined that all members of our Compensation Committee are independent (as independence is currently defined in Rule 5605(a)(2) of the Adviser (the “Voting Trust Agreement”)Nasdaq listing standards). No members of the Compensation Committee received compensation from us during the last fiscal year other than directors’ fees. Messrs. Outland, Adelgren and Wilkinson also serve on the compensation committees of Gladstone Commercial Corporation, Gladstone Land Corporation and Gladstone Investment Corporation. Our Board has determined that this simultaneous service does not impair the respective directors’ ability to effectively serve on our Compensation Committee.

Compensation Committee Interlocks and Insider Participation

No member of the Compensation Committee ever served as one of our executive officers. Further, none of our executive officers has ever served as a member of the Compensation Committee or as a director of another entity any of whose executive officers served on our Compensation Committee.

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Ethics, Nominating and Corporate Governance Committee

The Ethics Committee is responsible for identifying, reviewing and evaluating candidates to serve as our directors (consistent with criteria approved by our Board), pursuantreviewing and evaluating incumbent directors, recommending to which David Gladstone will deposit allour Board for selection candidates for election to our Board, making recommendations to our Board regarding the membership of his indirect intereststhe committees of our Board, assessing the performance of our Board, and developing our corporate governance principles. Our Ethics Committee charter can be found in the Adviser, which represented 100%Investors section of the voting and economic interests thereof, with the voting trust.

Pursuant to the Voting Trust Agreement, prior to its Effective Date (as defined below) David Gladstone will, in his sole discretion, have the full, exclusive and unqualified right and power to vote in person or by proxy all of the shares of common stock of the Adviser deposited with the voting trustour website at all meetings of the stockholders of the Adviser in respect of any and all matters on which the stockholders of the Adviser are entitled to vote under the Adviser’s certificate of incorporation or applicable law, to give consents in lieu of voting such shares of common stock of the Adviser at a meeting of the stockholders of the Adviser in respect of any and all matters on which stockholders of the Adviser are entitled to vote under its certificate of incorporation or applicable law, to enter into voting agreements, waive notice of any meeting of stockholders of the Adviser in respect of such shares of common stock of the Adviser and to grant proxies with respect to all such shares of common stock of the Adviser with respect to any lawful corporate action (collectively, the “Voting Powers”)www.gladstonecapital.com. Commencing on the Effective Date, the Voting Trust Board shall have the full, exclusive and unqualified right and power to exercise the Voting Powers. Each member of the Voting Trust Board shall hold 20%Ethics Committee is independent (as independence is currently defined in Rule 5605(a)(2) of the voting powerNasdaq listing standards).

Information Regarding the Process for Nominating Director Candidates

The Ethics Committee believes that candidates for director should have certain minimum qualifications, including being able to read and understand basic financial statements, being over 21 years of age and having the highest personal integrity and ethics. The Ethics Committee also considers such factors as possessing relevant expertise upon which to be able to offer advice and guidance to management, having sufficient time to devote to our affairs, demonstrated excellence in his or her field, having the ability to exercise sound business judgment and having the commitment to rigorously represent the long-term interests of our stockholders. However, the Ethics Committee retains the right to modify these qualifications from time to time. Candidates for director nominees are reviewed in the context of the Voting Trustcurrent composition of our Board, asour operating requirements and the long-term interests of our stockholders.

The Ethics Committee and Board believe that diversity is an important attribute of directors and that our Board should be the culmination of an array of backgrounds and experiences and be capable of articulating a variety of viewpoints. Accordingly, under the Ethics Committee charter (as amended and restated in May 2021), the Ethics Committee considers and discusses diversity in its annual review of the Effective Date. The “Effective Date” shall occurBoard and its review of director nominees. Factors considered by the Board in reviewing the diversity on our Board include honesty, loyalty, personal lifestyle, values, disciplines, ethics, age, experience, gender, race, ethnicity, culture, sexual orientation, expertise, background and skills, all in the context of an assessment of the perceived needs of us and our Board at that point in time in order to create and maintain a balance of knowledge, experience and capability that will best serve us and our stockholders. Similarly, upon the occurrence of any vacancy on the earliestBoard, the Ethics Committee will actively seek out highly qualified candidates (including female candidates and racially or ethnically diverse candidates) to include in the pool from which an ultimate nominee for director is chosen.

In the case of (i)incumbent directors whose terms of office are set to expire, the deathEthics Committee reviews such directors’ overall service to us during their term, including the number of David Gladstone, (ii) David Gladstone’s election (in his sole discretion)meetings attended, level of participation, quality of performance, and (iii) one year fromany other relationships and transactions that might impair such directors’ independence. In the case of new director candidates, the Ethics Committee also determines whether such new nominee must be independent for Nasdaq purposes, which determination is based upon applicable Nasdaq listing standards, applicable SEC rules and regulations and the advice of counsel, if necessary. The Ethics Committee then uses its network of contacts to compile a list of potential

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candidates, but may also engage, if it deems appropriate, a professional search firm. The Ethics Committee conducts any appropriate and necessary inquiries into the backgrounds and qualifications of possible candidates after considering the function and needs of our Board. The Ethics Committee meets to discuss and consider such candidates’ qualifications and then selects a nominee for recommendation to our Board by majority vote. To date, the Voting Trust AgreementEthics Committee has not paid a fee to any third party to assist in the process of identifying or evaluating director candidates.

Stockholder Recommendation of Director Candidates to the Ethics, Nominating and Corporate Governance Committee

The Ethics Committee will consider director candidates recommended by stockholders. The Ethics Committee does not intend to alter the manner in which it evaluates candidates, including the minimum criteria set forth above, based on whether the candidate was recommended by a stockholder or not. Stockholders who wish to recommend individuals for consideration by the Ethics Committee to become nominees for election to our Board may do so by delivering a written recommendation to our secretary at the address set forth on the cover page of this Proxy Statement and containing the information required by our Bylaws.

For nominations for election to our Board to be properly brought before an annual meeting by a stockholder, the stockholder must comply with the advance notice provisions and other requirements of Article II, Section 4 of our Bylaws. These notice provisions require that nominations for directors for the 2025 annual meeting must be received no earlier than the close of business on November 3, 2024 (90 days before the first anniversary of our 2024 Annual Meeting) and not later than the close of business on December 3, 2024 (60 days before the first anniversary of the 2024 Annual Meeting).

Submissions must include the full name of the proposed nominee, a description of the proposed nominee’s business experience for at least the previous five years, complete biographical information, a description of the proposed nominee’s qualifications as a director and a representation that the nominating stockholder is entered into. Following entry intoa beneficial or record owner of our stock. Any such submission must be accompanied by the Voting Trust Agreement,written consent of the currentproposed nominee to be named as a nominee and to serve as a director if elected. The Ethics Committee has not received or rejected a timely director nominee proposal from a stockholder or stockholders.

Stockholder Communications with the Board of Directors

Our Board has adopted a formal process by which our stockholders may communicate with our Board or any of our directors. Persons interested in communicating their concerns or issues may address correspondence to our Board, to a particular director, or to the independent directors generally, in care of Gladstone Capital Corporation, Attention: Investor Relations, at 1521 Westbranch Drive, Suite 100, McLean, Virginia 22102. This information is also contained in the Investors section of our website at www.gladstonecapital.com.

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Code of Ethics

We have adopted a Code of Ethics and Business Conduct (the “Code”) that applies to all of our officers and directors and to the employees of our Adviser and our Administrator. The Ethics Committee reviews, approves and recommends to our Board any changes to the Code. It also reviews any violations of the Code and makes recommendations to our Board on those violations. The Code is available in the Investors section of our website at www.gladstonecapital.com. If we make any substantive amendments to the Code or grant any waiver from a provision of the Code to any executive officer or director, we will promptly disclose the nature of the amendment or waiver on our website.

The Executive Committee

The Executive Committee, which is composed of Messrs. Gladstone (Chairman) and Parker, has the authority to exercise all powers of our Board except for actions that must be taken by a majority of independent directors or the full Board under applicable rules and regulations.

The Offering Committee

The Offering Committee is responsible for assisting our Board in discharging its responsibilities regarding the offering from time to time of our securities. The Offering Committee has all powers of our Board that are necessary or appropriate and may lawfully be delegated to the Offering Committee in connection with an offering of our securities. Our Offering Committee operates pursuant to a written charter, which can be found in the Investors section of our website at www.gladstonecapital.com.

The Valuation Committee

The Valuation Committee is responsible for assisting the Board in determining the fair value of our investment portfolio or other assets in compliance with the 1940 Act and assisting the Board’s compliance with legal and regulatory requirements, as well as risk management, related to valuation. The Valuation Committee operates pursuant to a written charter, which can be found in the Investors section of our website at www.gladstonecapital.com.

Oversight of Risk Management

Since September 2007, Jack Dellafiora has served as our chief compliance officer and, in that position, Mr. Dellafiora directly oversees our enterprise risk management function and reports to our chief executive officer, the Audit Committee and our Board in this capacity. Mr. Dellafiora also serves as chief compliance officer of Gladstone Commercial Corporation, Gladstone Land Corporation, Gladstone Investment Corporation, the Adviser, the Administrator and Gladstone Securities. Mr. Dellafiora also serves as a managing principal of and is on the board of managers of Gladstone Securities. In fulfilling his risk management responsibilities, Mr. Dellafiora works closely with our general counsel and other members of senior management of the Adviser will continue to manage the day-to-day aspects of the Adviser. Becauseincluding, among others, our chief executive officer, president, chief financial officer, treasurer and chief operating officer.

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David Gladstone indirectly beneficially owns greater than 25%Our Board, in its entirety, plays an active role in overseeing management of our risks. Our Board regularly reviews information regarding our credit, liquidity and operations, as well as the risks associated with each. Each of the voting sharesfollowing committees of our Board plays a distinct role with respect to overseeing management of our risks:

While each committee is responsible for evaluating certain risks and overseeing the management of such risks, the committees each report to our Board on a regular basis to apprise our Board regarding the status of remediation efforts of known risks and of any new risks that may have arisen since the previous report.

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PROPOSAL 2

RATIFICATION OF SELECTION OF INDEPENDENT REGISTERED PUBLIC

ACCOUNTING FIRM

The Audit Committee of our Board has selected PwC as the Company’s independent registered public accounting firm, which will audit the Company’s financial statements for the fiscal year ending September 30, 2024. The Board has further directed that management submit the selection of PwC as the Company’s independent registered public accounting firm for ratification by the stockholders at the annual meeting. PwC has audited the Company’s financial statements since its fiscal year ended September 30, 2003. Representatives of PwC are expected to be present at the annual meeting, will have an opportunity to make a statement if they so desire and will be available to respond to appropriate questions.

Neither our Bylaws nor other governing documents or law require stockholder ratification of the Company,selection of PwC as the Company’s independent registered public accounting firm. If the stockholders fail to ratify the selection, the Audit Committee will reconsider whether or not to retain PwC as the Company’s independent registered public accounting firm. Even if the selection is ratified, the Audit Committee, in its discretion and because all powersubject to vote these shares will be transferred to the Voting Trustapproval by our Board by the Voting Trust Agreement, a “change in control” of the Adviser will be deemed to have occurred underaccordance with the 1940 Act, as a result ofmay direct the occurrence of the Effective Date. However, all of the current key portfolio management personnel of the Adviser are currently expected to continue their relationship with the Adviser.

Section 2(a)(4) of the 1940 Act provides that the transferappointment of a controlling interest of an investment adviser,different independent registered public accounting firm at any time during the year if it determines that such as will be caused by thea change in control, constitutes an “assignment,” and Section 15(a) of the 1940 Act provides that any investment advisory contract must terminate on its “assignment.” Effective upon the change in control, the then-existing investment advisory agreement between the Company and the Adviser (the “Original Advisory Agreement”) will terminate. In order for the Adviser to continue serving as the Company’s investment adviser following the termination of the Original Advisory Agreement, the Company’s stockholders must approve a new investment advisory agreement for the Company. As a result, we are asking the Company’s stockholders to approve the New Advisory Agreement.

The 1940 Act requires that the New Advisory Agreement be approved by the Company’s stockholders in order for it to become effective. At an in-person meeting held August 22, 2023, the Board discussed whether it would be in the best interests of the Company to approve the New Advisory Agreement, to take effect as of the Effective Date. The Board, including all of the independent directors, unanimously approved the New Advisory Agreement and recommended that it be submitted to the Company’s stockholders for approval at the special meeting.

There are no changes to the terms of the Original Advisory Agreement in the New Advisory Agreement, including the fee structure and services to be provided, other than the date and term of the New Advisory Agreement as compared to the Original Advisory Agreement. In addition to there being no changes to the fee structure, no other fees or expenses currently paid by the Company will change as a result of entry into the New Advisory Agreement. There will be no changes to the Company’s principal investment objective, investment strategies, fundamental investment restrictions or principal risks as a result of entry into the Voting Trust Agreement or New Advisory Agreement.

If the Proposal is approved by the Company’s stockholders, the New Advisory Agreement will be entered into by the Company and the Adviser on the Effective Date. The Company will not execute the New Advisory Agreement if there is a change in control of the Adviser other than the one specifically described in this Proxy Statement, or other event that would cause the New Advisory Agreement to terminate pursuant to the 1940 Act, if already executed.

If the Proposal is not approved by the Company’s stockholders, the Board will consider alternatives for the Company, including seeking subsequent approval of a new investment advisory agreement by the Company’sits stockholders. If the Proposal is approved, but the Voting Trust Agreement is not entered into or the Effective Date does not occur, the Adviser will continue to serve as investment adviser to the Company pursuant to the Original Advisory Agreement.

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primary role in interviewing, vetting and negotiating employment contracts with candidatesAudit Fees. Audit fees include fees for services that normally would be provided by the accountant in connection with addingstatutory and retaining key portfolio company management team members.regulatory filings or engagements and that generally only the independent accountant can provide. In addition to fees for the audit of our annual financial statements and the review of our quarterly financial statements in accordance with generally accepted auditing standards, this category contains fees for comfort letters, statutory audits, consents, and assistance with and review of documents filed with the SEC.

Audit Related Fees. Audit related fees are assurance related services that traditionally are performed by the independent accountant that are reasonably related to the performance of the audit or review of our financial statements and are not reported under “Audit Fees.” These types of assurance services include attest services that are not required by statute or regulation.

Tax Fees. Tax fees include corporate and subsidiary compliance and consulting.

All Other Fees. Fees for other services would include fees for products and services other than the services reported above, including any non-audit fees.

During the fiscal years ended September 30, 2023 and September 30, 2022, the aggregate non-audit fees paid to PwC for services rendered to our Adviser and any entity controlling, controlled by or under common control with our Adviser that provides ongoing services to the Company were $[—] and $586,800, respectively. These fees were primarily for tax and compliance services. The Audit Committee has considered whether, and determined that, the rendering of these services to our Adviser and the entities controlling, controlled by or under common control with our Adviser is compatible with maintaining the independent registered public accounting firm’s independence.

non-contractually,Pre-Approval unconditionally,Policies and irrevocably creditsProcedures

The Audit Committee has adopted a policy and procedures for the pre-approval of audit and non-audit services rendered by our independent registered public accounting firm, PwC. The policy generally pre-approves specified services in the defined categories of audit services, audit-related services, and tax services up to specified amounts. Pre-approval may also be given as part of the Audit Committee’s approval of the scope of the engagement of the independent registered public accounting firm or on an individual explicit case-by-case basis before the independent registered public accounting firm is engaged to provide each service. The pre-approval of services may be delegated to one or more of the Audit Committee’s members, but the decision must be reported to the full Audit Committee at its next scheduled meeting.

The Audit Committee has determined that the rendering of the services other than audit services currently being provided by PwC is compatible with maintaining the independent registered public accounting firm’s independence.

During fiscal years 2023 and 2022, 100% of anyour audit fees associated with our independent registered public accounting firm were pre-approved by our Audit Committee.

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THE BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT STOCKHOLDERS VOTE “FOR” THE RATIFICATION OF PRICEWATERHOUSECOOPERS LLP AS THE COMPANY’S INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM FOR THE FISCAL YEAR ENDING SEPTEMBER 30, 2024.

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Report of the Audit Committee of the Board of Directors¹

The Audit Committee has reviewed and discussed the Company’s audited financial statements with management and PricewaterhouseCoopers LLP, the Company’s independent registered public accounting firm, with and without management present. The Audit Committee included in its review results of the independent registered public accounting firm’s examinations, the Company’s internal controls, and the quality of the Company’s financial reporting. The Audit Committee also reviewed the Company’s procedures and internal control processes designed to ensure full, fair and adequate financial reporting and disclosures, including procedures for such services againstcertifications by the base management feeCompany’s chief executive officer and chief financial officer that we would otherwise beare required to payin periodic reports filed by the Company with the Securities and Exchange Commission. The Audit Committee is satisfied that the Company’s internal control system is adequate and that the Company employs appropriate accounting and auditing procedures.

Management represented to the Adviser. The Adviser additionally non-contractually, unconditionally, and irrevocably credits back to us 100% ofAudit Committee that the loan servicing fees described below under “Certain Transactions – Loan Servicing Fees”. Our Board of Directors accepted a non-contractual, unconditional, and irrevocable credit from the Adviser to reduce the annual base management fee on syndicated loan participations to 0.5%, to the extent that proceeds resulting from borrowings were used to purchase such syndicated loan participations,Company’s consolidated financial statements for the year ended September 30, 2022.

After giving effect2023 were prepared in accordance with generally accepted accounting principles. The Audit Committee discussed with the independent registered public accounting firm the matters required to the amount of management fees credited back to usbe discussed under Auditing Standard No. 1301 (Communications with Audit Committees) as adopted by the Adviser,Public Company Accounting Oversight Board (“PCAOB”), which addresses communication between audit committees and independent registered public accounting firms. The Audit Committee has also received the written disclosures and the letter from the independent registered public accounting firm required by applicable requirements of the PCAOB regarding the independent registered public accounting firm’s communications with the audit committee concerning independence and has discussed with the independent registered public accounting firm the independent registered public accounting firm’s independence (Communications with Audit Committees). The Audit Committee discussed and reviewed with PricewaterhouseCoopers LLP the Company’s critical accounting policies and practices, internal controls, other material written communications to management, and the scope of PricewaterhouseCoopers LLP’s audit and all fees paid to PricewaterhouseCoopers LLP during the fiscal year. The Audit Committee adopted guidelines requiring review and pre-approval by the Audit Committee of audit and non-audit services performed by PricewaterhouseCoopers LLP for the Company.

The Audit Committee has reviewed and considered the compatibility of PricewaterhouseCoopers LLP’s performance of non-audit services with the maintenance of PricewaterhouseCoopers LLP’s independence as the Company’s independent registered public accounting firm and has concluded that independence has been maintained.

Based on the Audit Committee’s review and discussions referred to above, the Audit Committee recommended to our Board of Directors that the Company’s audited financial statements be included in the Company’s Annual Report on Form 10-K, for the fiscal year ended September 30, 2022,2023, for filing with the Securities and Exchange Commission. In addition, the Audit Committee has engaged

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PricewaterhouseCoopers LLP to serve as the Company’s independent registered public accounting firm for the fiscal year ending September 30, 2024.

Submitted by the Audit Committee

Anthony W. Parker, Chairperson

Michela A. English

John H. Outland

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PROPOSAL 3

APPROVE AN AMENDMENT TO THE COMPANY’S CHARTER TO INCREASE

THE NUMBER OF AUTHORIZED SHARES OF COMMON STOCK

On [●], 2023, the Board unanimously approved, subject to stockholder approval, an amendment (the “Charter Amendment”) to our charter (the “Charter”) to increase our authorized shares of common stock, $0.001 par value per share, from 44,000,000 to 74,000,000, with a corresponding increase in the number of authorized shares of capital stock, and proposed that the same be submitted to our stockholders for approval. The Charter Amendment will not change the par value of our common stock or the number of authorized shares of preferred stock, which currently consists of 6,000,000 authorized shares of 6.25% Series A Cumulative Redeemable Preferred Stock, $0.001 par value per share, none of which were issued and outstanding as of the record date for the meeting. Our Board believes that the increase in authorized shares of common stock and the Charter Amendment are advisable and in our best interest and has unanimously approved such action, subject to stockholder approval of the same. The text of the proposed Charter Amendment is set forth on Appendix A to this proxy statement.

The affirmative vote of two-thirds of the votes entitled to be cast by the holders of all common stock entitled to vote at the annual meeting is required to approve an amendment to our charter to increase the number of authorized shares of common stock. Abstentions will have the effect of a vote “AGAINST” this proposal; however, they will be counted towards the quorum requirement.

Purposes and Effects of Increasing the Number of Authorized Shares

As of the close of business on the record date, there were [●] shares of common stock issued and outstanding, out of 44,000,000 authorized shares. Our Board believes that it is desirable to have additional authorized but unissued shares of our common stock available for proper corporate purposes, including issuances of our common stock in public offerings registered under the Securities Act of 1933 and private placement transactions as well as for stock dividends or strategic and other transactions that may arise. As of the date of this proxy statement, other than the equity distribution agreement relating to the at-the-market offering of shares of our common stock, we have no agreements, commitments or plans with respect to the sale or issuance of any of the additional shares of common stock as to which authorization is sought. Shares of common stock with an aggregate offering price of up to $[●] may be sold under our at-the-market program at market prices prevailing at the time of sale, at prices related to prevailing market prices or negotiated prices. As of December [1], 2023, the last reported sales price for our common stock on The Nasdaq Global Select Market was $[●].

If approved, this proposal would allow us to issue additional shares of our common stock without further stockholder approval, unless required by applicable law or stock exchange rules. If our stockholders do not approve the Charter Amendment and we are unable to access the capital markets by issuing additional shares when attractive opportunities arise, our ability to grow over time and to continue to pay dividends to our stockholders could be adversely affected. We are not seeking stockholder approval to issue common stock at a price below net asset value per share at the annual meeting.

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The additional shares of common stock to be authorized by the Charter Amendment would be a part of the existing class of common stock and, if and when issued, would have rights and privileges identical to the currently issued and outstanding shares of common stock. Under our Charter, our stockholders do not have preemptive rights to subscribe for additional securities which may be issued by us and our Board has no plans to grant such rights with respect to such shares. Our Board may classify or reclassify any unissued shares of common stock into other classes or series of stock and establish the preferences, conversion or other rights, voting powers, restrictions, limitations as to dividends, qualifications and terms or conditions of redemption of any such stock.

If we issue additional shares of common stock or other securities convertible into common stock in the future, it could dilute the voting rights of existing holders of our capital stock and could also dilute earnings per share of existing holders of our common stock. In addition, if we issue additional shares of capital stock in the future, our Adviser will receive greater fees as result of the increased assets under management.

Articles of Amendment

If this proposal is approved, the Charter Amendment would become effective upon the acceptance for record of articles of amendment by the State Department of Assessments and Taxation of Maryland. We expect to file such articles of amendment promptly after the annual meeting. In such event, our Charter would be amended to reflect the increase in the number of authorized shares of common stock and the corresponding increase in the number of authorized shares of our capital stock.

THE BOARD, INCLUDING EACH OF THE INDEPENDENT DIRECTORS, UNANIMOUSLY RECOMMENDS THAT YOU VOTE “FOR” THE AMENDMENT TO THE COMPANY’S CHARTER TO INCREASE THE NUMBER OF AUTHORIZED SHARES OF COMMON STOCK.

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SECURITY OWNERSHIP OF

CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

The following table sets forth certain information regarding the ownership of the common stock of the Company as of November 30, 2023, by: (i) each current director; (ii) each of our named executive officers; (iii) all of our executive officers and directors as a group; and (iv) all those known by us to be beneficial owners of more than 5% of our common stock. Except as otherwise noted, the address of the individuals below is c/o Gladstone Capital Corporation, 1521 Westbranch Drive, Suite 100, McLean, VA 22102. As of November 30, 2023, no independent director (or his/her immediate family members) owned securities of our Adviser.

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The following table sets forth, as of November 30, 2023, the dollar range of equity securities that are beneficially owned by each of our directors in the Company and in both the Company and Gladstone Investment Corporation in the aggregate. Gladstone Investment Corporation is our affiliate and a business development company that is also externally managed by our Adviser.

Gladstone Commercial Corporation, our affiliate and a real estate investment trust, is also managed by our Adviser. The following table sets forth certain information regarding the ownership of the common and preferred stock of Gladstone Commercial Corporation as of November 30, 2023, by each independent incumbent director and nominee. As of November 30, 2023, none of our independent directors owns any class of stock of Gladstone Commercial Corporation, other than common stock.

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Gladstone Land Corporation, our affiliate and a real estate investment company, is also managed by our Adviser. The following table sets forth certain information regarding the ownership of the common stock of Gladstone Land Corporation as of November 30, 2023, by each independent incumbent director and nominee. As of November 30, 2023, none of our independent directors owns any preferred stock of Gladstone Land Corporation.

Insider Trading Policy

The Code adopted by the Company covers directors, officers and other employees of Gladstone Land Corporation, Gladstone Commercial Corporation or Gladstone Investment Corporation (collectively, with the Company, the “Funds”), the Company, the Administrator or the Adviser, earnedincluding such persons’ immediate family members (collectively, “Insiders”). The Code of Ethics establishes insider trading policies and procedures governing the purchase, sale, and/or other dispositions of the Company’s securities by the Company and Insiders and is reasonably designed to promote compliance with insider trading laws, rules and regulations, and any listing standards applicable to the Company.

The Code of Ethics also prohibits Insiders from entering into a short sale transaction or trading in options (including puts and calls), warrants, convertible securities, appreciation rights or other derivative securities, with respect to the Company’s securities (or securities of the Funds), or using any other derivative transaction or instrument to take a short position in respect of such Fund’s securities.

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EXECUTIVE COMPENSATION

Compensation Discussion and Analysis

None of our executive officers receives direct compensation from us. We do not currently have any employees and do not expect to have any employees in the foreseeable future. The services necessary for the operation of our business are provided to us by our officers and the other employees of our Adviser and Administrator, pursuant to the terms of the Advisory Agreement and Administration Agreement, respectively. Mr. Gladstone, our chairman and chief executive officer, Mr. Marcotte, our president, and Mr. Brubaker, our chief operating officer and assistant secretary, are all employees of and compensated directly by our Adviser. Ms. Schaltenbrand, our chief financial officer and treasurer, is an aggregate amountemployee of $13.0our Administrator.

During the fiscal year ended September 30, 2023, we incurred total fees of approximately $[—] million to our Adviser under the Original Advisory Agreement which represents management fees and incentive fees in$[—] million to our Administrator under the amountAdministration Agreement. For a discussion of $5.9 million and $7.1 million, respectively. The Newthe terms of our Advisory Agreement includesand Administration Agreement, see “Certain Transactions” below.

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DIRECTOR COMPENSATION

The following table shows for the same basefiscal year ended September 30, 2023 certain information with respect to the compensation of all directors that are not also executive officers. Our officers do not receive any compensation for their service as directors:

For our fiscal year ended September 30, 2023, as compensation for serving on our Board, each of our independent directors received an annual fee of $25,000, an additional $1,000 for each Board meeting attended, and an additional $1,000 for each committee meeting attended if such committee meeting took place on a day other than when the full Board met. In addition, the chairperson of the Audit Committee received an annual fee of $7,500, the chairpersons of the Compensation and Valuation Committees received an annual fee of $3,000, and the chairperson of the Ethics Committee received an annual fee of $1,000 for their additional services in these capacities. We also reimburse our directors for their reasonable out-of-pocket expenses incurred in attending Board and committee meetings.

We do not pay any compensation to directors who also serve as our officers, or as officers or directors of our Adviser or our Administrator, in consideration for their service to us. Our Board may change the compensation of our independent directors in its discretion. None of our independent directors received any compensation from us during the fiscal year ended September 30, 2023, other than for Board or committee service and meeting fees.

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Compensation Committee Report²

The Compensation Committee has reviewed and discussed with management feethe Compensation Discussion and incentive fee currentlyAnalysis (“CD&A”) contained in place underthis Proxy Statement. Based on this review and discussion, the Original Compensation Committee has recommended to the Board of Directors that the CD&A be included in this Proxy Statement and incorporated into the Company’s Annual Report on Form 10-K for the fiscal year ended September 30, 2023.

Submitted by the Compensation Committee

John H. Outland, Chairperson

Paul W. Adelgren

Walter H. Wilkinson, Jr.

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CERTAIN TRANSACTIONS

Advisory Agreement.and Administration Agreements

Management Fee

Under the Advisory Agreement, our Adviser is responsible for our day-to-day operations and administration, record keeping and regulatory compliance functions. Specifically, these responsibilities included (i) identifying, evaluating, negotiating and consummating all investment transactions consistent with our investment objectives and criteria; (ii) providing us with all required records and regular reports to our Board concerning our Adviser’s efforts on our behalf; and (iii) maintaining compliance with all regulatory requirements applicable to us. The base management fee pursuant to the Advisory Agreement is calculatedassessed at an annual rate of 1.75% computed on the basis of our gross assets, excluding cash and cash equivalents but including assets purchased with borrowed funds, and is payable quarterly in arrears. The base management fee is calculated based on the average value of the Company’sour gross assets at the end of the two most recently completed calendar quarters and appropriately adjusted for any share issuances or repurchases during(inclusive of the current calendar quarter. Base investment advisory fees forquarter), which are total assets, including investments made with proceeds of borrowings, less any partial monthuninvested cash or quarter are appropriately pro rated.

Incentive Fee

The incentive fee consists of two components, the income-based incentive fee and the capital gains-based incentive fee, that are independent of each other, with the result that one component may be payable even if the other is not.

cash equivalents resulting from borrowings. The Advisory Agreement also provides for an incentive fee, which consists of two parts: an income-based incentive fee and a capital gains-based incentive fee. The income-based incentive fee rewards the Adviser if our quarterly net investment income (before giving effect to any incentive fee) exceeds 1.75% (2.0% during the period from April 1, 2020 through March 31, 2023) of our net assets, which we define as total assets less liabilities and before taking into account any incentive fees payable or contractually due but not payable during the period (the “hurdle rate”), at the end of the immediately preceding calendar quarter. We pay our Adviser an income-based incentive fee with respect to our pre-incentive fee net investment income in each calendar quarter as follows:

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affiliated with them are entitled to indemnificationportfolio companies under certain agreements and may receive fees for services other than managerial assistance. Such services may include: (i) assistance obtaining, sourcing or structuring credit facilities, long term loans or additional equity from us for any damages, liabilities, costs and expenses (including reasonable attorneys’ fees and amounts reasonably paid in settlement) arising from the rendering of our Adviser’sunaffiliated third parties; (ii) negotiating important contractual financial relationships; (iii) consulting services under the Original Advisory Agreement and New Advisory Agreement, or otherwise as an investment adviser of ours.

Approval

The Original Advisory Agreement was most recently unanimously approved by the Board, including by eachregarding restructuring of the independent directors, on July 11, 2023,portfolio company and was last approved by the Company’s stockholders on December 2, 2005.

Executive Officersfinancial modeling as it relates to raising additional debt and Directors of the Adviser

Information regarding the directorsequity capital from unaffiliated third parties; and principal executive officers of the Adviser before(iv) taking a primary role in interviewing, vetting and after the change of control is set forth below.negotiating employment contracts with candidates in connection with adding and retaining key portfolio company management team members. The Adviser is 100% indirectly ownednon-contractually, unconditionally, and controlled by David Gladstone. David Gladstone ownsirrevocably credits 100% of any fees for such services against the voting and economic interests of The Gladstone Companies, Ltd., which in turn owns 100% ofbase management fee that we would otherwise be required to pay to the voting and economic interests of The Gladstone Companies, Inc., which in turn owns 100% of the voting and economic interests of the Adviser. The address of David Gladstone, the Adviser and its executive officers is 1521 Westbranch Drive, Suite 100, McLean, Virginia 22102. The following are the directors and executive officers of the Adviser and employees of the Adviser who are officers or directors of the Company:

Before the Change of Control

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pursuant to the Original Advisory Agreement cannot exceed 1.75% of total assets (including investments made with proceeds of borrowings, less any uninvested cash and cash equivalents resulting from borrowings) during any given calendar year, we treat payment of the loan servicing fee pursuant to our line of credit as a pre-payment of a portion of the base management fee under the Original Advisory Agreement. Accordingly, these loan servicing fees are 100% voluntarily, irrevocably and unconditionally credited back to us by the Adviser. Loan servicing fees of approximately $6.3 million $[—] were incurred for the fiscal year ended September 30, 2022,2023, all of which were directly credited against the amount of the base management fee due to our Adviser under the Original Advisory Agreement.

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Indemnification

In our articles of incorporationcharter and bylaws, we have agreedare required to indemnify certaineach of our officers and directors, by providing, among other things, that we will indemnify such officer or director, under the circumstances and to the extent provided for therein, for expenses, damages, judgments, fines and settlements he or she may be required to pay in actions or proceedings which he or she is or may be made a party by reason of his or her position as our director, officer or other agent, to the fullest extent permitted under Maryland law, and our bylaws.as limited by the 1940 Act. Notwithstanding the foregoing, the indemnification provisions shall not protect any officer or director from liability to us or our stockholders as a result of any action that would constitute willful misfeasance, bad faith or gross negligence in the performance of such officer’s or director’s duties, or reckless disregard of his or her obligations and duties.

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OTHER MATTERS

Our Board of Directors knows of no other matters that will be presented for consideration at the specialannual meeting. If any other matters are properly brought before the meeting, it is the intention of the persons named in the accompanying proxy to vote on such matters in accordance with their best judgment.

We will furnish, without charge, a copy of our Annual Report on Form 10-K for the year ended September30, 2022, including consolidated financial statements, but not including exhibits, to each of our stockholders of record on October 18, 2023, and to each beneficial stockholder on that date upon written request made to our secretary at 1521 Westbranch Drive, Suite 100, McLean, Virginia 22102 or by calling toll-free (866) 366-5745. Such request must set forth a good faith representation that the requesting party is a beneficial owner of our common stock. The Annual Report with exhibits is also available at no cost through the SEC’s EDGAR database available at www.sec.gov.

SUBMISSION OF STOCKHOLDER PROPOSALS

We will consider for inclusion in our proxy materials for the 2024 annual meeting proposals that we receive not later than August 18, 2023 and that comply with all applicable requirements of Rule 14a-8 promulgated under the 1934 Act, and our bylaws. Stockholders must submit their proposals to our secretary at 1521 Westbranch Drive, Suite 100, McLean, Virginia 22102.

In addition, any stockholder who wishes to propose a nominee to our Board or propose any other business to be considered by the stockholders (other than a stockholder proposal to be included in our proxy materials pursuant to Rule 14a-8 of the 1934 Act) must comply with the advance notice provisions and other requirements of Article II, Section 4(b) of our bylaws, a copy of which is on file with the SEC and may be obtained without charge from our secretary upon request.

These notice provisions require that nominations of persons for election to our Board and proposals of business to be considered by the stockholders for the 2024 annual meeting must be made in writing and submitted to our secretary at the address above no earlier than November 4, 2023 (90 days before the first anniversary of our 2023 annual meeting) and not later than December 4, 2023 (60 days before the first anniversary of the 2023 annual meeting). You are also advised to review our bylaws, which contain additional requirements about advance notice of stockholder proposals and director nominations.discretion.

October 26,December 15, 2023

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ExhibitAppendix A

INVESTMENT ADVISORY AND MANAGEMENT AGREEMENT

BETWEEN

GLADSTONE CAPITAL CORPORATION

ANDARTICLES OF AMENDMENT

GLADSTONE MANAGEMENT CORPORATION

AGREEMENTis made this [●] day of [●] 20[●], by and between Gladstone Capital Corporation, a Maryland corporation (the “FundCorporation”), hereby certifies to the State Department of Assessments and Gladstone ManagementTaxation of Maryland that:

FIRST: The charter of the Corporation a Delaware corporation (the “AdviserCharter”). is hereby amended by deleting the first two sentences of paragraph A of Article FOURTH and inserting in lieu thereof the following sentences:

WHEREAS, the FundThe Corporation has authority to issue 80,000,000 shares of capital stock, consisting of 74,000,000 shares of Common Stock, $0.001 par value per share, and 6,000,000 shares of 6.25% Series A Cumulative Redeemable Preferred Stock, $0.001 par value per share. The aggregate par value of all authorized shares of stock having par value is a closed-end management investment company that has elected to be treated as a business development company under the Investment Company Act of 1940, as amended (the “Investment Company Act”);$80,000.

WHEREAS, the Adviser is an investment adviser that has registered under the Investment Advisers Act of 1940, as amended (the “Advisers Act”);

WHEREAS, the Fund has previously retained the Adviser to provide investment advisory services with respectSECOND: The amendment to the Fund pursuant to that certain Fourth Amended and Restated Investment Advisory and Management Agreement, dated April 12, 2022 (the “Prior Agreement”); and

WHEREAS, concurrent with the termination of the Prior Agreement, the Fund desires to continue to retain the Adviser to furnish investment advisory services to the Fund on the terms and conditions hereinafterCharter as set forth and the Adviser wishes to be retained to provide such services.

NOW, THEREFORE, in consideration of the premises and for other good and valuable consideration, the parties hereby agree as follows:

(a) The Fund hereby employs the Adviser to act as the investment adviser to the Fund and to manage the investment and reinvestment of the assets of the Fund, subject to the supervision ofabove has been duly advised by the Board of Directors of the Fund, forCorporation and approved by the period and upon the terms herein set forth, (i) in accordance with the investment objective, policies and restrictions that are set forth in the Fund’s filings with the Securities and Exchange Commission,(ii) in accordance with the Investment Company Act and (iii) during the term of this Agreement in accordance with all other applicable federal and state laws, rules and regulations, and the Fund’s articles of incorporation and by-laws. Without limiting the generalitystockholders of the foregoing,Corporation as required by law.

THIRD: The total number of shares of stock which the Adviser shall, during the term and subjectCorporation had authority to issue immediately prior to the provisions of this Agreement, (i) determine the compositionforegoing amendment of the portfolioCharter was 50,000,000 shares of stock, consisting of 44,000,000 shares of Common Stock, $0.001 par value per share (the “Common Stock”), and 6,000,000 shares of 6.25% Series A Cumulative Redeemable Preferred Stock, $0.001 par value per share (the “Series A Preferred Stock”). The aggregate par value of all shares of stock having par value was $50,000.

FOURTH: The total number of shares of stock which the Corporation has authority to issue pursuant to the foregoing amendment of the Fund, the natureCharter is 80,000,000 shares of stock, consisting of 74,000,000 shares of Common Stock and timing6,000,000 shares of Series A Preferred Stock. The aggregate par value of all shares of stock having par value is $80,000.

FIFTH: The information required by Section 2-607(b)(2)(i) of the changes therein andMaryland General Corporation Law is not changed by the manner of implementing such changes; (ii) identify, evaluate and negotiate the structureforegoing amendment of the investmentsCharter.

SIXTH: The undersigned officer acknowledges these Articles of Amendment to be the corporate act of the Corporation and, as to all matters or facts required to be verified under oath, the undersigned acknowledges that, to the best of such officer’s knowledge, information and belief, these matters and facts are true in all material respects and that this statement is made byunder the Fund; (iii) close and monitor the Fund’s investments; (iv) determine the securities and other assets that the Fund will purchase, retain, or sell; (v) perform due diligence on prospective portfolio companies; and (vi) provide thepenalties for perjury.

[SIGNATURE PAGE FOLLOWS]

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Fund with such other investment advisory, research and related services asIN WITNESS WHEREOF, the Fund may, from time to time, reasonably require for the investmentCorporation has caused these Articles of its funds. The Adviser shall have the discretion, power and authority on behalf of the Fund to effectuate its investment decisions for the Fund, including the execution and delivery of all documents relating to the Fund’s investments and the placing of orders for other purchase or sale transactions on behalf of the Fund. In the event that the Fund determines to acquire debt financing, the Adviser will arrange for such financing on the Fund’s behalf, subject to the oversight and approval of the Fund’s Board of Directors. If it is necessary for the Adviser to make investments on behalf of the Fund through a special purpose vehicle, the Adviser shall have authority to create or arrange for the creation of such special purpose vehicle and to make such investments through such special purpose vehicle in accordance with the Investment Company Act.

(b) The Adviser hereby accepts such employment and agrees during the term hereof to render the services described herein for the compensation provided herein.

(c) Subject to the requirements of the Investment Company Act, the Adviser is hereby authorized to enter into one or more sub-advisory agreements with other investment advisers (each, a “Sub-Adviser”) pursuant to which the Adviser may obtain the services of the Sub-Adviser(s) to assist the Adviser in fulfilling its responsibilities hereunder. Specifically, the Adviser may retain a Sub-Adviser to recommend specific securities or other investments based upon the Fund’s investment objective and policies, and work, along with the Adviser, in structuring, negotiating, arranging or effecting the acquisition or disposition of such investments and monitoring investments on behalf of the Fund, subject to the oversight of the Adviser and the Fund. The Adviser, and not the Fund, shall be responsible for any compensation payable to any Sub-Adviser. Any sub-advisory agreement entered into by the Adviser shall be in accordance with the requirements of the Investment Company Act and other applicable federal and state law and shall contain a provision requiring the Sub-Adviser to comply with sections 1(e) and 1(f) below as if it were the Adviser.

(d) The Adviser shall for all purposes herein provided be deemedAmendment to be an independent contractorexecuted in its name and except as expressly provided or authorized herein, shall have no authority to act for or represent the Fund in any way or otherwise be deemed an agent of the Fund.

(e) The Adviser shall keep and preserve for the period required by the Investment Company Act any books and records relevant to the provision of its investment advisory services to the Fund and shall specifically maintain all books and records with respect to the Fund’s portfolio transactions and shall render to the Fund’s Board of Directors such periodic and special reports as the Board may reasonably request. The Adviser agrees that all records that it maintains for the Fund are the property of the Fund and will surrender promptly to the Fund any such records upon the Fund’s request, provided that the Adviser may retain a copy of such records.

(f) The Adviser has adopted and implemented written policies and procedures reasonably designed to prevent violation of the Federal Securities laws by the Adviser. The Adviser has provided the Fund, and shall provide the Fund at such times in the future as the Fund shall reasonably request, with a copy of such policies and procedures and a report of such policies and procedures. Such report shall be of sufficient scope and in sufficient detail, as may reasonably be required to comply with Rule 38a-1 under the Investment Company Act and to provide reasonable assurance that any material inadequacies would be disclosed by such examination, and, if there are no such inadequacies, the report shall so state.

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(ii) Base Management Fees payable for any partial month or quarter will be appropriately prorated.

(i) One part will be calculated and payable quarterly in arrears based on the pre-Incentive Fee net investment income for the immediately preceding calendar quarter. For this purpose, pre-Incentive Fee net investment income means interest income, dividend income and any other income (including any other fees, such as commitment, origination, structuring, diligence, consulting fees that the Fund receives from portfolio companies, but excluding fees for providing managerial assistance) accrued by the Fund during the calendar quarter, minus the Fund’s operating expenses for the quarter (including the Base Management Fee (less any rebate of other fees received by the Adviser), expenses payable under the Administration Agreement between the Fund and the Administrator and any interest expense and dividends paid on any issued and outstanding preferred stock, but excluding the Incentive Fee). Pre-Incentive Fee net investment income includes, in the case of investments with a deferred interest feature (such as original issue discount, debt instruments with payment-in-kind interest and zero coupon securities), accrued income that the Fund has not yet received in cash. Pre-Incentive Fee net investment income does not include any realized capital gains, realized capital losses or unrealized capital appreciation or depreciation. Pre- Incentive Fee net investment income, expressed as a rate of return on the value of the Fund’s net assets at the end of the immediately preceding calendar quarter, will be comparedPreliminary Proxy - Subject to a “hurdle rate” of 1.75% per quarter (7% annualized). The Fund will pay the Adviser an Incentive Fee with respect to the Fund’s pre-Incentive Fee net investment income in each calendar quarter as follows: (1) no Incentive Fee in any calendar quarter in which the Fund’s pre-Incentive Fee net investment income does not exceed the hurdle rate; (2) 100% of the Fund’s pre-Incentive Fee net investment income with respect to that portion of such pre-Incentive Fee net investment income, if any, that exceeds the hurdle rate but is less than 2.1875% in any calendar quarter (8.75% annualized); and (3) 20% of the amount of the Fund’s pre-Incentive Fee net investment income, if any, that exceeds 2.1875% in any calendar quarter (8.75% annualized).

(ii) The second part of the Incentive Fee (the “Capital Gains Fee”)will be determined and payable in arrears as of the end of each fiscal year (or upon termination of this Agreement as set forth below), commencing on September 30, 2007, and will equal 20.0% of the Fund’s realized capital gains, if any, computed net of all realized capital losses and unrealized capital depreciation at the end of such year. The amount of capital gains used to determine the Capital Gains Fee shall be calculated at the end of each applicable year by subtracting the sum of the Fund’s Cumulative Aggregate Realized Capital Losses and Aggregate Unrealized Capital Depreciation from the Fund’s Cumulative Aggregate Realized Capital Gains (each as defined in Section 3(b)(iii) below). If this number is positive at the end of such year, then the Capital Gains Fee for such year will be equal to 20.0% of such amount, less the aggregate amount of any Capital Gains Fees paid in all prior years. In the event that this Agreement shall terminate as of a date that is not a fiscal year end, the termination date shall be treated as though it were a fiscal year end for purposes of calculating and paying a Capital Gains Fee.

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