McLean, Virginia

December 17, 2021September [●], 2023

ALL OF OUR STOCKHOLDERS ARE CORDIALLY INVITED TO ATTEND THE ANNUALSPECIAL MEETING VIA WEBCAST. WHETHER OR NOT YOU PLAN TO ATTEND THE ANNUALSPECIAL 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 ANNUALSPECIAL 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 ANNUALSPECIAL MEETING).

Proposal 2, 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 annualspecial 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 annualspecial meeting, who will separately count “FORALL,” “WITHHOLD ALL,” and “FOR ALL EXCEPT” 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 each proposalthe Proposal are described below under the question “How many votes are needed to approve each proposal?the 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.

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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 our outstanding shares of common stock are represented by stockholders present at the meeting or by proxy. On the record date there were 34,304,371[●] shares of common stock outstanding and entitled to vote. Thus, 17,152,186[●] 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. Withhold votes, abstentions and broker non-votesAbstentions will be counted towards the quorum requirement. Broker non-votes will not be treated as shares present for quorum purposes. If there is no quorum, the stockholders present and entitled to vote at the meeting may adjourn the meeting to another date.

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

Preliminary voting results will be announced at the annualspecial meeting. Final voting results will be published in a Current Report on Form 8-K that we expect to file with the U.S. Securities and Exchange Commission (“SEC”) within four business days after the annualspecial 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 2023 annual meeting proposals that we receive not later than August 19, 2021 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 2023 annual meeting must be made in writing and submitted to our secretary at the address above no earlier than November 5, 2022 (90 days before the first anniversary of our 2022 Annual Meeting) and not later than December 5, 2022 (60 days before the first anniversary of the 2022 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?

Gladstone Capital CorporationThe Adviser 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.

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What proxy materials are available on the Internet?

The Notice of the AnnualSpecial Meeting and Proxy Statement are also available at www.proxyvote.com.

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Nominees for a Three-Year Term to Expire at the 2025 Annual Meeting of StockholdersControl

Directors Continuing in Office Until the 2023 Annual Meeting of Stockholders

Directors Continuing in Office Until the 2024 Annual Meeting of Stockholders

Executive Officers and Certain Other Officers Who Are Not Directors

After the Change of Control

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Qualifications of Director Nominees

When considering whether our director nominees 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:

Qualifications of Incumbent Directors Serving Until the 2023 or 2024 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:

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

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 six directors are independent directors within the meaning of the applicable Nasdaq listing standards: Messrs. Adelgren, Outland, Parker, and Wilkinson and Mses. English and Merrick. 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 Mr. Brubaker, the vice chairman of our Board and our chief operating officer and assistant secretary, are not independent directors by virtue of their positions as officers of the Company and our Adviser and their employment by our Adviser.

MeetingsRecommendation of the Board of Directors

Our Board met four times during fiscal year 2021. Each Board member attended 75% or more of the aggregate of the meetings of our Board and of the committees on which he or she served that were held during fiscal year 2021.

Our independent directors met four times during fiscal year 2021 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. OurThe Board believes that our chief executive officer is best situated to serve as chairman because he is the director most familiar with our businessterms 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 mobilizationconditions of the Adviser’s resources at our Board’s behestNew Advisory Agreement are fair to, and on its behalf.

Information Regarding Committees of the Board of Directors

The following table identifies our standing committees and their current members, all of which also served on such committees during the fiscal year ended September 30, 2021, and the number of meetings held by each committee during the fiscal year ended September 30, 2021:

terminate the existing independent registered public accounting firm or to appoint and engage a new independent registered public accounting firm; reviews and approves the retention of the independent registered public accounting firm to perform any proposed permissible non-audit services; monitors the rotation of partners of the independent registered public accounting firm on our audit engagement team as required by law; confers with management and the independent registered public accounting firm regarding the effectiveness of internal controls over financial reporting; establishes procedures, as required under applicable law, for the receipt, retention and treatment of complaints received by us regarding accounting, internal accounting controls or auditing matters and the confidential and anonymous submission by employees of concerns regarding questionable accounting or auditing matters; and meets to review our annual audited financial statements and quarterly financial statements with management and the independent registered public accounting firm, including reviewing our disclosures under “Management’s Discussion and Analysis of Financial Condition and Results of Operations.” The Audit Committee has adopted a written charter that is available to stockholders in the Investors section of our website at www.gladstonecapital.com.

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 Nasdaq 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 that Messrs. Adelgren, Outland, Parker and Wilkinson and Mses. English and Merrick each qualify as an “audit committee financial expert,” as defined in applicable SEC rules. Our Board made a qualitative assessment of the members’ level of knowledge and experience based on a number of factors, including formal education and experience. Messrs. Parker and Outland and Mses. English and Merrick also serve on the audit committees of Gladstone Commercial Corporation, Gladstone Land Corporation, Gladstone Investment Corporation and Gladstone Acquisition Corporation. Our Board has determined that this simultaneous service does not impair the respective directors’ 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, usthe Company and ourits stockholders. The committee considersBoard believes that, upon stockholder approval of the Proposal, the Adviser will continue providing the same level of services as it currently provides under the Original Advisory Agreement. The Board was presented with information demonstrating that the New Advisory Agreement would enable the Company’s stockholders to continue to obtain quality services at a cost that was fair and reasonable.

The Board noted that the terms of the New Advisory Agreement, including the fees payable thereunder, are identical to those of the Original Advisory Agreement relating to the Company. The Board considered that the services to be provided and the standard of care under the New Advisory Agreement are the same as the Original Advisory Agreement. The Board noted the change in control of the Adviser does not alter the Adviser’s responsibilities and that the Adviser had indicated that it did not anticipate any material changes to the services provided to the Company as a result of the change in control. The Board also observed that approval of the New Advisory Agreement now would allow for continuity of the provision of services to the Company in the event of the death of Mr. Gladstone.

In considering the New Advisory Agreement, the Board took into consideration (i) the nature, extent and quality of the advisory and other services provided by the Adviser under the Original Advisory Agreement; (ii) historical performance of the Company; (iii) comparative data with respect to advisory fees or similar expenses paid by other business development companies with similar investment objectives; (iv) the Company’s projected operating expenses and expense ratio compared to business development companies with similar investment objectives; (v) any existing and potential sources of indirect income to the Adviser or the Administrator from their relationships with the Company and the profitability of those relationships; (vi) information about the services to be performed and the personnel performing such periodic reviews,services under the Original Advisory Agreement; (vii) the organizational capability and financial condition of the Adviser and its affiliates; (viii) the Adviser’s practices regarding the selection and compensation of brokers that may execute the Company’s portfolio transactions and the brokers’ provision of brokerage and research services to the Adviser; (ix) the possibility of obtaining similar services from other third party service providers or through an internally managed structure; and (x) other factors the Board deemed to be relevant. In its deliberations, the Board did not identify any single piece of information discussed below that was all-important, controlling or determinative of its decision.

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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.provided.

Ethics, NominatingExperience of Management Team and Corporate Governance CommitteePersonnel

The Ethics Committee is responsible for identifying, reviewing and evaluating candidates to serve as our directors (consistent with criteria approved by our Board), reviewing and evaluating incumbent directors, recommending to our Board for selection candidates for election to our Board, making recommendations to our Board regardingdiscussed the membershipexperience of current key personnel of the committees of ourAdviser and its affiliates. The Board assessing the performance of our Board, and developing our corporate governance principles. Our Ethics Committee charter can be found in the Investors section of our website at www.gladstonecapital.com. Each member of the Ethics Committee is independent (as independence is currently defined in Rule 5605(a)(2) of the Nasdaq listing standards).

Information Regarding the Process for Nominating Director Candidates

The Ethics Committee believesconsidered 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 contextall of the current composition of our Board, our 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 reviewkey portfolio management personnel of the Board 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 orderAdviser are currently expected 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 Board, 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 incumbent directors whose terms of office are set to expire, the Ethics Committee reviews such directors’ overall service to us duringcontinue their term, including the number of meetings attended, level of participation, quality of performance, and any 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 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 Ethics 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 complyrelationship 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 2023 annual meeting must be received no earlier than November 5, 2022 (90 days before the first anniversary of our 2022 Annual Meeting) and not later than December 5, 2022 (60 days before the first anniversary of our 2022 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 a beneficial or record owner of our stock. Any such submission must be accompanied by the written consent of the proposed 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.

Code of Ethics

We have adopted a Code of Business Conduct and Ethics (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.Adviser.

The Executive CommitteeHistorical Performance

The Executive Committee, which is composed of Messrs. Gladstone (Chairman), Brubaker and Parker, has the authority to exercise all powers of our Board except for actionsconsidered 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, LLC. Mr. Dellafiora also serves ashas demonstrated a managing principalstrong track record of and is on the board of managers of Gladstone Securities, LLC. In fulfilling his risk management responsibilities, Mr. Dellafiora works closely with our general counsel and other members of senior management including, among others, our chief executive officer, president, chief financial officer, treasurer and chief operating officer.

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,funding portfolio companies as well as the risks associated with each. Eachhistorical management of the following committeesCompany by the Adviser. Based on the information reviewed, the Board concluded that it was satisfied by the historical performance of our Board plays a distinct role with respect to overseeing management of our risks:the Adviser.

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While each committee is responsible for evaluating certain risksfinancially able to provide the Company with the services enumerated in the New Advisory Agreement.

The Board considered the extent to which economies of scale may be realized as the Company grows, but concluded that material economies of scale are unlikely given the amount of time and overseeingeffort involved in originating investments consistent with the managementCompany’s current investment strategy limits the Company’s ability to realize economies of such risks,scale regardless of the committees each reportCompany’s size.

Conclusion

No single factor was determinative of the Board’s decision to ourapprove the New Advisory Agreement; rather, the Board based its determination on the total mix of information available to it. Based on a regular basisconsideration of all the factors in their totality, the Board, including a majority of the independent directors, determined that the New Advisory Agreement, including the compensation payable under the agreement, was fair and reasonable 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.

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, 2022.Company. 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 ratificationincluding each of the selectionindependent directors, therefore determined that the approval 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 subject to approval by our Board in accordance with the 1940 Act, may direct the appointment of a different independent registered public accounting firm at any time during the year if it determines that such a change would beNew Advisory Agreement was in the best interests of the Company and its stockholders.

The affirmative vote of a majority of the votes cast at the annual meeting will be required to ratify the selection of PwC. Abstentions and broker non-votes will be considered present and entitled to vote for the purpose of determining whether a quorum exists, although they will not be counted for any purpose in determining whether this matter has been approved.

Independent Registered Public Accounting Firm Fees

The following table represents the aggregate amount of fees capitalized or expensed by the Company for the fiscal years ended September 30, 2021 and September 30, 2020 that were billed by PwC, our principal independent registered public accounting firm.

Audit Fees. Audit fees include fees for services that normally would be provided by the accountant in connection with statutory and 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, 2021 and September 30, 2020, 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 $328,335 and $328,482, respectively. These fees were for 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.

Pre-Approval Policies and Procedures

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 2021 and 2020, 100% of our audit fees associated with our independent registered public accounting firm were pre-approved by our Audit Committee.

THE BOARD, INCLUDING EACH OF THE INDEPENDENT DIRECTORS, UNANIMOUSLY RECOMMENDS THAT STOCKHOLDERSYOU VOTE “FOR” THE RATIFICATION OF PRICEWATERHOUSECOOPERS LLP AS THE COMPANY’S INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM FOR THE FISCAL YEAR ENDING SEPTEMBER 30, 2022.

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 certifications by the Company’s chief executive officer and chief financial officer that are required in 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 Audit Committee that the Company’s consolidated financial statements for the year ended September 30, 2021 were prepared in accordance with generally accepted accounting principles. The Audit Committee discussed with the independent registered public accounting firm the matters required to be discussed under Auditing Standard No. 1301 (Communications with Audit Committees) as adopted by the 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 audits 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.APPROVAL OF THE NEW ADVISORY AGREEMENT.

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, 2021, for filing with the Securities and Exchange Commission. In addition, the Audit Committee has engaged PwC to serve as the Company’s independent registered public accounting firm for the fiscal year ending September 30, 2022.

Submitted by the Audit Committee

Anthony W. Parker, Chairperson

Caren D. Merrick

Michela A. English

John H. Outland15

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 vice chairman, 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 employee of our Administrator.

During the fiscal year ended September 30, 2021, we incurred total fees of approximately $11.5 million to our Adviser under the Advisory Agreement and $1.4 million to our Administrator under the Administration Agreement. For a discussion of the terms of our Advisory Agreement and Administration Agreement, see “Certain Transactions” below.18

DIRECTOR COMPENSATION

The following table shows for the fiscal year ended September 30, 2021 certain information with respect to the compensation of all directors that are not also executive officers. Our executive officers do not receive any compensation for their service as directors:

Compensation Committee Report²

The Compensation Committee has reviewed and discussed with management the Compensation Discussion and Analysis (“CD&A”) contained in this Proxy Statement. Based on this review and discussion, the Compensation Committee has recommended to our Board of Directors that the CD&A be included in this Proxy Statement and incorporated into our Annual Report on Form 10-K for the fiscal year ended September 30, 2021.

Submitted by the Compensation Committee

John H. Outland, Chairperson

Paul W. Adelgren

Walter H. Wilkinson, Jr.

financial relationships; (iii) consulting services regarding restructuring of the portfolio company and financial modeling as it relates to raising additional debt and equity capital from unaffiliated third parties; and (iv) taking a primary role in interviewing, vetting and negotiating employment contracts with candidates in connection with adding and retaining key portfolio company management team members. The Adviser non-contractually, unconditionally, and irrevocably credits 100% of any fees for such services against the base management fee that we would otherwise be required to pay to the Adviser; however, pursuant to the terms of the Advisory Agreement, a small percentage of certain of such fees, totaling $0.1 million for the years ended September 30, 2021 and 2020 was retained by the Adviser in the form of reimbursement, at cost, for tasks completed by personnel of the Adviser primarily for the valuation of portfolio companies.

Under the Administration Agreement, we pay separately for administrative services including record keeping and regulatory compliance functions. Payments under the Administration Agreement are equal to our allocable portion of our Administrator’s overhead expenses in performing its obligations under the Administration Agreement, including rent for the space occupied by our Administrator, and our allocable portion of the salaries, bonuses, and benefits expenses of our chief financial officer, treasurer, chief valuation officer, chief compliance officer, general counsel and secretary and their respective staffs. Our allocable portion of the Administrator’s expenses are generally derived by multiplying our Administrator’s total expenses by the approximate amount of time the Administrator’s employees perform services for us in relation to their time spent performing services of all companies serviced by our Administrator under contractual agreements.

Our Adviser and Administrator areis 100% indirectly owned and controlled by David Gladstone, the chairman of our Board and our chief executive officer. Mr. Gladstone is also the chairman of the board of directors and chief executive officer of our Adviser. Terry Lee Brubaker, our vice chairman, chief operating officer and assistant secretary, is a member of the board of directors of our Adviser and its vice chairman, chief operating officer and assistant secretary. Ms. Novara, a member of our Board, is Head of Human Resources, Facilities & Office Management and IT of our Adviser. Although we believe that the terms of the Advisory Agreement and Administration Agreement are no less favorable to us than those that could be obtained from unaffiliated third parties in arms’ length transactions, our Adviser and Administrator, their officers and their directors have a material interest in the terms of these agreements.

The principal executive office of each of the Adviser and the Administrator is located at 1521 Westbranch Drive, Suite 100, McLean, Virginia 22102.

Loan Servicing Fee

The Adviser also services the loans held by Gladstone Business Loan, LLC (“Business Loan”), the borrower under our line of credit, in return for which the Adviser receives a 1.5% annual fee payable monthly based on the aggregate outstanding balance of loans pledged under our line of credit. Since Business Loan is a consolidated subsidiary of ours, and the total base management fee paid to the Adviser 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 $5.6$6.3 million were incurred for the fiscal year ended September 30, 2021,2022, 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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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. 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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GLADSTONE CAPITAL CORPORATION 1521 WESTBRANCH DRIVE, SUITE 100 MCLEAN, VA 22102 SCAN TO VIEW MATERIALS & VOTE Proxy Card For Common Stockholders VOTE BY INTERNET Before The Meeting - Go to www.proxyvote.com or scan the QR Barcode above Use the Internet to transmit your voting instructions and for electronic delivery of information up until 11:59 p.m. Eastern Time the day before the cut-off date or meeting date. Have your proxy card in hand when you access the web site and follow the instructions to obtain your records and to create an electronic voting instruction form. During The Meeting - Go to www.virtualshareholdermeeting.com/GLAD2022 You may attend the meeting via the Internet and vote during the meeting. Have the information that is printed in the box marked by the arrow available and follow the instructions. VOTE BY PHONE - 1-800-690-6903 Use any touch-tone telephone to transmit your voting instructions up until 11:59 p.m. Eastern Time the day before the cut-off date or meeting date. Have your proxy card in hand when you call and then follow the instructions. VOTE BY MAIL Mark, sign and date your proxy card and return it in the postage-paid envelope we have provided or return it to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717. TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS: KEEP THIS PORTION FOR YOUR RECORDS D63307-P64239 THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED. DETACH AND RETURN THIS PORTION ONLY GLADSTONE CAPITAL CORPORATION The Board of Directors recommends you vote FOR the following: 1. Election of Directors Nominees: 01) Paul W. Adelgren 02) John H. Outland 03) David Gladstone For All Withhold All For All Except To withhold authority to vote for any individual nominee(s), mark “For All Except” and write the number(s) of the nominee(s) on the line below. The Board of Directors recommends you vote FOR the following proposal: For Against Abstain 2. To ratify our Audit Committee’s selection of PricewaterhouseCoopers LLP as our independent registered public accounting firm for our fiscal year ending September 30, 2022. Please sign exactly as your name(s) appear(s) hereon. When signing as attorney, executor, administrator, or other fiduciary, please give full title as such. Joint owners should each sign personally. All holders must sign. If a corporation or partnership, please sign in full corporate or partnership name by authorized officer. Signature [PLEASE SIGN WITHIN BOX] Date Signature (Joint Owners) Date

Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting:The Notice and Proxy Statement and Annual Report are available at www.proxyvote.com. D63308-P64239 GLADSTONE CAPITAL CORPORATION Annual Meeting of Stockholders February 3, 2022 - 11:00 a.m. Eastern Time This proxy is solicited by the Board of Directors PROXY FOR COMMON SHARES The undersigned hereby appoints Nicole Schaltenbrand and Michael LiCalsi, and each of them acting individually, as attorneys and proxies of the undersigned, with full power of substitution, to vote all of the shares of stock of Gladstone Capital Corporation which the undersigned may be entitled to vote at the 2022 Annual Meeting of Stockholders of Gladstone Capital Corporation to be held virtually at www.virtualshareholdermeeting.com/GLAD2022, on Thursday, February 3, 2022 at 11:00 a.m. Eastern Time, and at any and all postponements, continuations and adjournments thereof, with all powers that the undersigned would possess if personally present, upon and in respect of the matters on the reverse side, and in accordance with the instructions, with discretionary authority as to any and all other matters that may properly come before the meeting. Unless a contrary direction is indicated, this proxy will be voted in favor of each of the nominees listed in Proposal 1and in favor of Proposal 2 as more specifically described in the proxy statement. If specific instructions are indicated, this proxy will be voted in accordance therewith. Continued and to be signed on reverse side