Notice of Annual Meeting of Shareholders

The 20232024 Annual Meeting of Shareholders of Trustmark Corporation (Trustmark) will be held as follows:

DATE AND TIME Tuesday, April 25, 2023,23, 2024, at 1:00 p.m. CT   LOCATION Trustmark Corporate Office 248 East Capitol Street Jackson, Mississippi 39201    ITEMS OF BUSINESS 1)  To elect a board of 11 directors to hold office for the ensuing year or until their successors are elected and qualified. 2)  To provide advisory approval of Trustmark’s executive compensation. 3)  To provide an advisory vote onapprove the frequency of advisory votes on Trustmark’s executive compensation.Trustmark Corporation Stock and Incentive Compensation Plan. 4)  To approve an amendment and restatement of Trustmark’s articles of incorporation to provide for exculpation of directors in accordance with Mississippi law. 5)  To ratify the selection of Crowe LLP as Trustmark’s independent auditor for the fiscal year ending December 31, 2023.2024. 6)5)  To transact such other business as may properly come before the meeting.

RECORD DATE

Shareholders of record on March 1, 2023,2024, are entitled to notice of and to vote at the Annual Meeting.

PROXY VOTING/REVOCATION

Your vote is important. You are urged to vote your shares as soon as possible, whether or not you plan to attend the meeting. Please vote your shares in one of the following ways:

If you attend the meeting, you may revoke your proxy prior to the voting thereof. You may also revoke your proxy by following the instructions on page 45 of the proxy statement.

Granville Tate, Jr.

Secretary

March 15, 202313, 2024

March 15, 202313, 2024

Dear Shareholder:

On behalf of your Board of Directors, we cordially invite you to attend Trustmark’s Annual Shareholders’ Meeting at Trustmark’s Corporate Office, 248 East Capitol Street, Jackson, Mississippi 39201, on April 25, 2023,23, 2024, at 1:00 p.m. CT. At the meeting, you will have the opportunity to elect 11 directors who bring diverse perspectives and valuable leadership skills to Trustmark. Their guidance will enable us to successfully compete in an evolving industry and continue our steadfast commitment to the customers, associates, shareholders, and communities we have the privilege of serving. Your vote is important to us. The proposals to be considered are described in this proxy statement, and instructions on how to vote your shares may be found on page 4.5. We encourage you to vote your shares in advance of the meeting to ensure the presence of a quorum.

We madecontinued to make significant progress across the organization during the year. LoanOur performance reflected solid loan production and credit quality, and continued deposit growth in 2022 was the highestan increasingly competitive marketplace. We achieved double-digit growth in Trustmark’s history. Credit quality remained strong. Netnet interest income and the net interest margin were up significantly. Ourin 2023 while noninterest income continued to expand thanks in part to another record year in our insurance business posted another record year.and commendable results in our banking, mortgage banking and wealth management businesses. We made significanthave a tremendous team of associates focused on expanding customer relationships and demonstrating the value Trustmark can provide as their trusted financial partner. Looking forward, we will continue to pursue opportunities to further leverage investments in technology including conversionthat will broaden our reach, enhance the customer experience, and improve efficiency. We remain focused on providing the financial services and advice our customers have come to a state-of-the-art loan system designed to enhance efficiency and productivity. With all of these positive advancements, our financial results were overshadowed by a settlement that, pending court approval, will resolve all current and potential future claims relating to litigation involving the Stanford Financial Group that began in 2009. While we expressly deny any liability or wrongdoing with respect to this matter, we believe the settlement is in the best interest of Trustmark and our shareholders as it eliminates risk, ongoing expense and uncertainty. With this matter now behind us, we will focus more intently on the future and the opportunities that are ahead. Trustmark is very well-positioned to serve and expand its customer base and createexpect while building long-term value for our shareholders.

We invite you to review our Form 10-K and our 20222023 Year in Review, both of which are available at investorrelations.trustmark.com or in hard copy upon request. These documents will provide more detailed information about your company.

Thank you for your continued support of Trustmark and your participation in this important process.

Sincerely,

Gerard R. Host Chair of the Board		Duane A. Dewey President and Chief Executive Officer

TABLE OF CONTENTS

PROXY SUMMARY

This summary highlights information contained elsewhere in this proxy statement. Please read the entire proxy statement carefully before voting as this is only a summary.

Information About the 20232024 Annual Meeting

Proposals

Financial Highlights – 20222023

1

Corporate Governance Highlights

1

23

GENERAL INFORMATION

Introduction

Trustmark Corporation (Trustmark) is holding its 20232024 Annual Meeting of Shareholders (the Annual Meeting) on Tuesday, April 25, 2023.23, 2024. This proxy statement is being sent on or about March 15, 2023,13, 2024, in connection with the solicitation by the Board of proxies to be voted at the Annual Meeting and at any adjournment or postponement thereof.

Trustmark is furnishing this proxy statement over the Internet to most shareholders. These shareholders will not receive printed copies of the proxy statement and proxy card, and instead will receive a Notice of Internet Availability of Proxy Materials containing instructions on how to access the proxy materials over the Internet. If you received a Notice of Internet Availability of Proxy Materials, please see “Availability of Proxy Materials” on page 4855 for additional information.

Meeting Location, Date and Time

The Annual Meeting will be held at Trustmark’s Corporate Office located at 248 East Capitol Street, Jackson, Mississippi 39201 on Tuesday, April 25, 2023,23, 2024, at 1:00 p.m. CT. To obtain directions to attend the meeting, contact the Secretary at 1-601-208-5088 or toll-free at 1-800-844-2000 (extension 5088).

Shareholders Entitled to Vote

Shareholders of record at the close of business on March 1, 2023,2024, are entitled to notice of and to vote at the Annual Meeting. On the record date, Trustmark had outstanding 61,048,51661,178,366 shares of common stock.

Required Vote

A majority of the shares outstanding and entitled to vote constitutes a quorum to transact business at the Annual Meeting. Each share is entitled to one vote on each proposal.

The required vote for each proposal is as follows:

While abstentions and broker non-votes are counted as shares present at the meeting for purposes of determining a quorum, they are not otherwise counted and, therefore, will have no effect on the outcome of the election of directors or any other proposal.

Applicable rules determine whether proposals presented at shareholder meetings are considered routine or non-routine. If a proposal is considered routine, a bank, broker or other holder of record, which holds shares for an owner in street name generally may vote on the proposal without receiving voting instructions from the beneficial owner. If a proposal is non-routine, the bank, broker or other holder of record generally may vote on the proposal only if the beneficial owner has provided voting instructions. A “broker non-vote” occurs when a broker or other entity returns a signed proxy card but does not vote shares on a particular proposal because the proposal is not a routine matter and the broker or other entity has not received voting instructions from the beneficial owner of the shares. The ratification of the selection of Crowe as independent auditor is considered a routine matter, while the other proposals, i.e., the election of directors, the advisory vote to approve Trustmark’s executive compensation, the advisory vote on the frequency of advisory votes on executive compensation, and the amendmentapproval of the Trustmark Corporation Stock and restatement of Trustmark’s articles of incorporation,Incentive Compensation Plan, are considered non-routine matters.

All valid proxies received by Trustmark will be voted in accordance with the instructions indicated in such proxies. As noted above, if you hold your shares through a bank, broker or other holder of record and you do not give voting instructions, your bank, broker or other record holder of the shares is not permitted to vote your shares on any proposal other than Proposal 5,4, which is the only routine proposal on the agenda. If no instructions are indicated in an otherwise properly executed proxy, it will be voted FOR each director nominee named in Proposal 1, FOR advisory approval of Trustmark’s executive compensation in Proposal 2, for a frequency of every ONE YEAR for the advisory vote on executive compensation in Proposal 3, FOR approval of the amendmentTrustmark Corporation Stock and restatement of Trustmark’s articles of incorporationIncentive Compensation Plan in Proposal 4,3, FOR ratification of the selection of Crowe as independent auditor in Proposal 54 and on all other matters in accordance with the recommendations of the Board.

34

How to Vote

Shareholders of record can vote at the Annual Meeting or by proxy without attending the Annual Meeting.

To vote by proxy:

If you hold your shares through a bank, broker or other holder of record, your bank, broker or other holder of record will provide you with materials and instructions for voting your shares. If you hold your shares through a bank, broker or other holder of record, and you plan to vote your shares at the Annual Meeting, you should complete the voting instructions form that the bank, broker or other holder of record will provideprovided to you or use the telephone or Internet voting arrangementsoptions described on the voting instructions form or other materials that the bank, broker or other holder of record will provideprovided to you.

You will receive multiple Notices of Internet Availability or printed copies of the proxy materials if you hold your shares in different ways (e.g., individually, by joint tenancy, through a trust or custodial account, etc.) or in multiple accounts. Please vote the shares represented by each Notice of Internet Availability or proxy card you receive to ensure that all of your shares are voted.

Revoking Your Proxy

If you are a shareholder of record, you may revoke your proxy at any time before the shares are voted by proxy during the meeting. A shareholder may revoke a proxy by delivering written notice to the Secretary at or prior to the Annual Meeting or by timely delivery to the Secretary of a subsequently dated proxy card or by submitting a later vote by Internet or smartphone (instructions are on the Notice of Internet Availability or the proxy card). In the case of multiple submissions regarding the same shares, the proxy with the latest date will be counted. The address for the Secretary is c/o Trustmark Corporation, Post Office Box 291, Jackson, MS 39205.

If you hold your shares through a bank, broker or other holder of record, your ability to revoke your proxy depends on the voting procedures of the bank, broker or other holder of record. Please follow the directions provided to you by your bank, broker or other holder of record.

Voting on Other Matters

The Board is not aware of any additional matters to be brought before the meeting. If other matters do come before the meeting, the persons named in the accompanying proxy or their substitutes will vote the shares represented by such proxies in accordance with the recommendations of the Board.

CORPORATE GOVERNANCE

Overview

During 2022, the Board undertook a comprehensive review of its governance structure and processes. As a result of such review, the Board approved a number of structural and procedural changes in order to enhance the Board’s effectiveness in providing oversight and strategic advice to management. The key structural changes involve a re-organization of several Board committees and a re-allocation of responsibilities amongst such committees. These changes took effect on January 1, 2023, and the descriptions of each committee’s responsibilities below reflect the re-organized committee structure as of such date. In addition to the committee changes, the Board has implemented a number of changes to the Board and committee processes designed to expand Board engagement and provide additional focus on value-enhancing and forward-looking activities.

Trustmark’s revised governance structure enables the Board to morefocus on value-added and forward-looking activities to effectively and efficiently address key, specific issues such as business growth, human capital, enterprise risk management, and technology, among others. This is accomplished through six standing Board committees and through the effective use of the directors’ combined wisdom, diverse experience, and business knowledge.

4

Key Features of Trustmark’s Corporate Governance

Trustmark’s governance structure has a number of key features that are designed to ensure effective and efficient oversight of the company, including the following:

The Code of Conduct for Trustmark Directors, Code of Ethics for Senior Financial Officers of Trustmark, Code of Ethics and Procedure to Report Violations of Law or Accounting or Audit Irregularities (Whistleblower Procedures) are available at investorrelations.trustmark.com or may be obtained, without charge, by written request addressed to the Secretary, Trustmark Corporation, Post Office Box 291, Jackson, MS 39205. Trustmark intends to provide required disclosure of any amendment to or waiver of its codes of conduct/ethics that applies to the chief executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, at investorrelations.trustmark.com promptly following any such amendment or waiver. Trustmark may also elect to disclose any such amendment or waiver in a report on Form 8-K filed with the Securities and Exchange Commission (SEC). The information contained on or connected to Trustmark’s website is not incorporated by reference in this proxy statement and should not be considered part of this or any other document that Trustmark files with the SEC.

Meetings of the Board of Directors

The Board met 10 times in 2022.2023. Each director attended at least 90%83% of the total number of meetings of the Board and Board committees of which the director was a member in 2022.2023. The Board meets jointly with the Board of Directors of Trustmark National Bank (the Bank Board), and since 2017, all members of the Board have also served as members of the Bank Board.

5

Board Leadership

Under Trustmark’s governance guidelines, which are contained in the Board Charter, the Board has the responsibility to determine the most appropriate leadership structure for the company, including whether it is best for the company at a given point in time for the roles of Board Chair and CEO to be separate or combined.

Mr. Dewey succeeded Mr. Host as CEO of Trustmark and the Bank on January 1, 2021, at which time Mr. Host became Executive Chairman of Trustmark and the Bank. In his role as Executive Chairman, Mr. Host focused on issues involving board governance, corporate strategy, corporate development, investor relations, industry engagement and civic leadership. Following the 2022 annual meeting of shareholders, Mr. Host ceased serving as Executive Chairman, and became Board Chair.

Trustmark’s Board Charter and Bylaws provide that if the Board Chair and CEO positions are occupied by the same individual or if the Board Chair is otherwise not independent, the Board’s Lead Director, who is independent, shall serve as Chair of the Executive Committee and Nominating & Governance Committee. Mr. Host is not considered to be independent due to his prior tenures as CEO and Executive Chairman. Mr. Puckett has served as the Chair of the Executive Committee, Nominating Committee, and as of 2023, the Nominating & Governance Committee, and Lead Director since the 2020 annual meeting of shareholders. The Lead Director’s responsibilities include (i) chairing meetings and executive sessions of the independent directors, Executive Committee, Nominating & Governance Committee and meetings on matters for which the Board Chair recuses himself and other meetings in the Board Chair’s absence, (ii) coordinating with the Board Chair to develop Board meeting agendas and schedules, (iii) communicating with and advising the Board Chair, (iv) referring to the appropriate Board committee any issue brought to his attention by shareholders, directors or others, (v) serving as the primary communicator between the independent directors and the CEO and (vi) providing an alternative communication channel for all directors. The Board believes an independent Lead Director serves an important function in providing independent leadership of the Board and strengthening the Board’s oversight of Trustmark’s business. The Board Charter is posted at investorrelations.trustmark.com.

Committees of the Board of Directors

As of January 1, 2023, thereThere are six standing Board committees: Audit, Enterprise Risk, Executive, Finance, Human Resources and Nominating & Governance. Each of these Board committees are joint committees of the Board and the Bank Board. The Audit, Enterprise Risk, Human Resources and Nominating & Governance committees are comprised solely of independent directors and otherwise satisfy the requirements applicable to such committees under Nasdaq listing standards.

Audit Committee

The Audit Committee meets regularly throughout the year, including meeting with the external and internal auditors without management present. All members of the Committee are independent directors as defined by Nasdaq Listing Rules. The Committee’s responsibilities include:

6

The purpose and responsibilities of the Audit Committee are described in greater detail in its Charter, which is posted at investorrelations.trustmark.com.

Enterprise Risk Committee

The Enterprise Risk Committee is responsible for ensuring that Trustmark has policies and processes to identify and manage various risks throughout the company. All members of the Committee are independent directors as defined by Nasdaq Listing Rules. The Committee’s responsibilities include:

The purpose and responsibilities of the Enterprise Risk Committee are described in greater detail in its Charter, which is posted at investorrelations.trustmark.com.

Executive Committee

The Executive Committee acts on behalf of the Board if a matter requires Board action between regularly scheduled Board meetings. It also evaluates and makes recommendations to the Board regarding material corporate transactions and approves unplanned expenditures greater than $1 million if the Finance Committee is unable to meet.

The purpose and responsibilities of the Executive Committee are described in greater detail in its Charter, which is posted at investorrelations.trustmark.com.

Finance Committee

The Finance Committee is responsible for overseeing Trustmark’s budgeting, capital planning and related financial strategy. The Committee’s responsibilities include:

The purpose and responsibilities of the Finance Committee are described in greater detail in its Charter, which is posted at investorrelations.trustmark.com.

8

Human Resources Committee

The Human Resources Committee is responsible for overseeing the development of a program to compensate Trustmark’s management in accordance with Trustmark’s compensation philosophy and objectives. The Committee also ensures that appropriate policies and practices are in place to facilitate the development of associate and management talent and orderly CEO succession. All members of the Committee during 2023 were and currently are “non-employee directors” within the meaning of Rule 16b-3 under the Securities Exchange Act of 1934 (the Exchange Act), “outside directors” within the meaning of Section 162(m) of the Internal Revenue Code of 1986, as amended, and “independent directors” within the meaning of Rule 5605(a)(2) of the Nasdaq Listing Rules.

In fulfilling its role, the Committee’s responsibilities include:

7

The Board and the Enterprise Risk Committee will request supplemental reports from Trustmark’s management with regard to risk management and risk mitigation strategies as appropriate. This reporting and governance structure ensures that information from the Enterprise Risk Committee, the other committees of the Board and the Bank Board, and management is analyzed and reported to the Board, and enables the Board and its committees to coordinate the risk oversight role, particularly with respect to risk interrelationships.

The Board provides oversight of management’s efforts to address cybersecurity risk by receiving periodic reports at meetings of the Enterprise Risk Committee and Audit Committee, as well as presentations at the Board level. These reports to the Board and its Committees address the threat environment, vulnerability assessments, specific cyber incidents and management’s efforts to monitor, detect and prevent cyber threats.

8

Trustmark’s bylaws permit direct nominations by shareholders. Therefore, the Nominating & Governance Committee does not have a policy for considering nominations by shareholders other than through the bylaw process outlined above. However, if a shareholder wishes to recommend an individual for Board service, rather than directly nominate the individual as set forth above, the shareholder may submit the individual’s name to the Nominating & Governance Committee by email to boardofdirectors@trustmark.com, or in writing addressed to Trustmark Corporation Nominating & Governance Committee, Post Office Box 291, Jackson, MS 39205. In order to give the Nominating & Governance Committee adequate time to consider any such individual for nomination as a director at the 20242025 Annual Meeting of Shareholders, such recommendations should be delivered no later than October 1, 2023.2024. In considering an individual recommended by a shareholder but not directly nominated, the Nominating & Governance Committee will use the same guidelines as set forth in the Director Qualifications section below.

When identifying potential candidates for director nominees, the Nominating & Governance Committee may solicit suggestions from incumbent directors, management or others.

Corporate Social Responsibility/Environmental, Social and Governance/Corporate Social Responsibility (ESG/CSR)Governance (CSR/ESG)

Trustmark believes that a company’s commitment to corporate social responsibility is measured by its sustainability, environmental, and societal impact. These factors are critical to long-term business viability. Trustmark understands that a company’s performance must be measured not only by shareholder returns, but also by how it achieves ESG/CSR objectives. The company employs a Director of Corporate Social Responsibility to monitor the continuing effectiveness of its program. RobustActive community engagement, informed policies and procedures, and responsible philanthropy are some of the ways in which Trustmark continues to serve its communities and workforce. Accomplishments in these areas of focus wereare highlighted in Trustmark’s first annual CSR Impact Report, published in 2022 andwhich is available at Trustmark.com.

Board Oversight.The Board has responsibility for overseeing Trustmark’s strategies, policies, and programs relating to ESG/CSRCSR/ESG matters, including environmental sustainability, community development and reinvestment andactivities, charitable giving, environmental sustainability, and other programs with social impacts. The Human Resources Committee reviews and approves Trustmark’s policies and practices regarding social responsibilitypertaining to workforce management issues relating to human resources, such as equal opportunity employment, diversity and inclusion.inclusion initiatives.

CSR Engagement and Investment.The company’s strategically aligned activities reflect its core values of Integrity, Service, Accountability, Relationships and Solutions. Trustmark’s continued commitment to corporate social responsibility was demonstrated in 20222023 through services provided to customers, partnerships formed in communities, and opportunities presented to associates. The company’s strategically aligned activities reflect its core values of Integrity, Service, Accountability, Relationships and Solutions. In 2022,2023, Trustmark invested more than $4$2.7 million in the form of contributions and sponsorships to local organizations, including a $1.5organizations. An additional $1.3 million tax credit investment was allocated to 13ten Mississippi youth and family-based charities providing services and programs for the welfare and development of children as part of Trustmark’s commitment underinvolvement in the Mississippi Children’s Promise Act.

Trustmark continued to focus on financial literacy and community outreach in 2022,2023, with associates volunteering more than 6,5195,990 hours of service to local partners through positions on non-profit boards of directors, financial literacy outreach and other forms of community engagement. The company also continued to partner with EVERFI, Inc., to provide online financial literacy courses in schools throughout Mississippi, to educate more than 4,500 students on financial matters through Trustmark’s Financial Scholars Program. The company’s partnership with EVERFI, Engage platform wasInc. also made available toprovides free online financial education through the Trustmark associates to conduct community-based financial literacy sessions, both in-person and virtually.Financial Education Tool Kit, accessible at Trustmark.com.

Additional financial literacy support was provided through Trustmark’s continued partnership with Operation HOPE, Inc., a national non-profit organization. Trustmark continued to engage with the organization, in 2022 to implementprovided additional financial literacy support through the HOPE Inside programProgram within the markets of Memphis, Tennessee; Montgomery, Alabama; and Jackson, Mississippi to provideMississippi. The program provides banking customers and members of the public with opportunities to receive financial tools and education to strengthen their financial security.security from within Trustmark branches. Trustmark’s investment of $200,000 in each of these designated markets providesrepresents a two-year commitment to support a dedicated financial wellness coach to administer the HOPE Inside program.Program. The coaches conduct financial literacy seminars, individualized financial counseling sessions and provide referrals to disaster relief services. These services and resources are provided at no cost to community residents, and extend towhich includes city employees and first responders in each of the designated markets. In 2022,2023, more than 3,3205,000 services were provided through Trustmark’s partnership with Operation HOPE.HOPE, Inc.

Trustmark valuesprioritizes partnerships that serve diverse communities and it embracespursues opportunities to engage in that work. In 2022,2023, Trustmark participated in collaborative partnerships with twocontinued its pledge to support minority depository institutions (MDIs), through the Project Roundtable for Economic Access and Change (REACh) Initiative,REACh, a program developed by the OCC. Project REACh aims to identify and reduce barriers to full, fair participation in the nation’s banking system and the economy to help expand access to credit and capital.

10

loans, $542$423 million in small business loans and small farm loans and more than $172$115 million in community development loans. Also in 2022, Trustmark also provided low-to-moderate income borrowers with more than $510$452 million in home mortgage loans.

The company’s collaborative work with community service providers, developers, realtors, housing advocates and others resulted in more than $34.5$33 million in investments that support and provide affordable housing, employment and community services for those with low-to-moderate incomes. Southern Community Capital (SCC), Trustmark’s community development entity and wholly-owned subsidiary, guides much of Trustmark’s work in this area by investing in projects in economically distressed areas through the New Markets Tax Credit (NMTC) program. Since its founding in 2012, SCC has deployed more than $130 million in NMTC allocations throughout Trustmark’s service area. Trustmark also enhanced its mortgage product offerings during the year2023 to meet the special credit needs of low-to-moderate income individuals and communities. Trustmark employs a dedicated team of associates to provide oversight of initiatives that advance financial growth and stability within racially and economically diverse communities. The Diverse Market Strategy Team coordinates with business units at Trustmark to develop innovative lending strategies, inclusive outreach events, targeted marketing campaigns, and special purpose products and programs to meet the unique needs of diverse communities throughout the company’s footprint.

Human Capital and Workforce Diversity.Trustmark’s commitment to serve diverse communities extends to its workforce practices. Trustmark’s Diversity Officer worksis positioned within the Human Resources Department to develop and oversee diverse training, recruitment and retention practices. The company has introduced several initiatives to support a workforce culture of diversity through educational diversity training for management and all associates, including the development of a training course that emphasizes management’s role in hiring a diverse and inclusive workforce. Three HR associates hold a Diversity, Equity and Inclusion certificate from the University of South Florida’s Muma College of Business and, in 2022, represented Trustmark in the American Bankers Association’s Black Bankers Employee Resource Group. Trustmark also continues to socialize cultural observances through a community calendar of events to promote a culture of inclusivity and engagement among associates. Trustmark has also introduced several initiatives to support a workforce culture of diversity through training for management and all associates. New training courses were developed in 2023 to emphasize associates’ roles in supporting a diverse and inclusive workforce and the value of being part of a multi-generational workforce. Trustmark’s talent team continued to execute a diverse recruitment strategy throughout the year which included outreach to local and state agencies, campus recruitment at historically black colleges and universities (HBCUs), forming strategic partnerships with leading housing organizations and holding employer advisory board memberships at local universities. Additionally in 2022,2023, three Human Resources associates represented Trustmark in the American Bankers Association’s Black Bankers Employee Resource Group. Trustmark also launched its secondthe third cycle of the Emerging Talent Program designedin 2023, to identify and develop high-performing associates through management mentorship.

Environmental Sustainability.Throughout the year, Trustmark promoted environmental sustainability through business practices that conserve natural resources including the sponsorship of numerous community shredding events to encourage recycling initiatives.and reduce energy consumption. Trustmark also provides shredding services at all buildings and branch locations, offers enhanced digital banking options and processes for customers, and utilizes internal workflow management systems to reduce paper usage. Additionally, an LED light conversion project was continued across the organization in 2022 to increase energy efficiency, in which 15 additionalTwelve Trustmark buildings were retrofitted in 2023 with LED lighting. Programmablelighting in an ongoing light conversion project to increase energy efficiency. LED lighting, as well as programmable thermostats and HVAC control systems previously installed in Trustmark buildings to conserve and monitor energy use have resulted in usage declines between 25-40 percent. Trustmark also purchased its first gas electric hybrid fleet vehicle in 2023 with plans to add additional vehicles as part of an ongoing initiative to reduce its carbon footprint. Trustmark’s proactive environmental business practices were matched with its responsivenessreflected in the company’s response to weather-induced events in 20222023 through the activation of comprehensive disaster recovery and business continuity plans. The plans detail the responsibilities of key positions, instructions on ways to continue operations throughout the progression of weather-related events, and timeframes by which key tasks must be accomplished. Trustmark is committed to assessing environmental risks to its operations, including those associated with increasing climate change concerns.

Additionally, the company commenced operation at a new Switch data center to store and manage its back up data in August 2023. Switch data centers provide enhanced cyber and physical security protections. The centers are cost efficient, provide scalability to adjust to changing business needs and they are also designed with sustainability features such as solar panels that help reduce greenhouse gas emissions. All Switch data centers have operated on 100% renewable energy since 2016.

Director Qualifications

The Board believes that in order to appropriately carry out its roles, directors must demonstrate a variety of personal traits, leadership qualities and individual competencies. In considering nominees submitted by the Board or management and any recommendations submitted by shareholders, the Nominating & Governance Committee will use these personal traits, leadership qualities and individual competencies to assess future director nominees’ suitability for Board service. The Nominating & Governance Committee also evaluates each director nominee’s qualities in the context of how that nominee would relate to the Board as a whole, in light of the Board’s current composition and Trustmark’s evolving needs.

Although Trustmark has no formal policy regarding diversity, the Nominating & Governance Committee believes that the Board should include directors with diverse skills, experience and business knowledge, and whose backgrounds, ages, geographical representation and community involvement contribute to an overall diversity of perspective that enhances the quality of the Board’s deliberations and decisions. The Nominating & Governance Committee may consider these factors as it deems appropriate in connection with the general qualifications of each director nominee.

12

Personal Traits

Board service is an extremely important, high-profile role and carries with it significant responsibility. For that reason, it is important that all directors possess a certain set of personal traits, including:

11

Board Diversity

The chart below provides information regarding the diversity characteristics of the members of our Board, based on self-identification by the directors.

1314

PROPOSAL 1: ELECTION OF DIRECTORS

The Board has fixed the number of directors for the coming year at 11.

The nominees listed herein have been proposed by the Board for election at the Annual Meeting. Shares represented by valid proxies will, unless authority to vote is withheld, be voted in favor of the proposed slate of 11 nominees. Directors must receive a majority of the votes cast in order to be elected (that is, the number of shares voted “for” a director must exceed the number of shares voted “against” that director). If a nominee who is an incumbent director is not elected to the Board, and no successor is elected, such nominee must tender his or her resignation to the Board. The Nominating & Governance Committee will then make a recommendation to the Board on whether to accept or reject the resignation or whether to take other action. The director who tenders his or her resignation may not participate in the recommendation of the Nominating & Governance Committee or the decision of the Board with respect to his or her resignation. Each director is elected to hold office until the next annual meeting of shareholders or until a successor is elected and qualified.

The Board recommends that shareholders vote “FOR” the proposed nominees.

The Nominees

		Adolphus B. Baker, 6667 Director of Trustmark since 2007 (Independent Director)Director)   Trustmark Corporation Committees: ·   Human Resources (Chair) ·   Nominating & Governance		Career Highlights: ·   Chairman, Cal-Maine Foods, Inc. (Producer and Distributor of Shell Eggs)   Other Public Company Boards: ·   Cal-Maine Foods, Inc.

Experience and qualifications: Mr. Baker is chairman and former chief executive officer of a publicly-traded company that is the largest producer and distributor of shell eggs in the United States. His position has provided him with significant business leadership skills and experience in evaluating strategic alternatives that focus on maximizing shareholder value. Mr. Baker’s years of service as a director of the Bank, and particularly as the former chair of the Bank Board’s Asset/Liability Committee (the responsibilities of which are now performed by the Finance Committee), provide him with an intrinsic understanding of Trustmark’s strategy for managing liquidity, which is a skill essential to the Board’s risk oversight function. He is a member of the National Association of Corporate Directors.

		William A. Brown, 6566 Director of Trustmark since 2017 (Independent Director)   Trustmark Corporation Committees: ·   Audit ·   Enterprise Risk		Career Highlights: ·   Chairman, Brown Group Holdings, Inc. (Soft Drink Manufacturing)   ·   President, Brown Bottling Group, Inc. (Beverage Distributor)

Experience and qualifications: Mr. Brown serves as chairman of a soft drink manufacturing business and president of a regional beverage distributor based in Mississippi. He serves on the Boards of the Pepsi Cola Bottlers Association and Wis-Pak/WP Beverages as well as trade associations, including the Mississippi Beverage Association. His extensive experience in this industry has provided him with significant marketing and business leadership skills as well as in-depth understanding of the business climate and customer base in significant Trustmark markets. Mr. Brown also served as Chair of the Bank Board’s Credit Policy Committee (the responsibilities of which are now performed by the Enterprise Risk Committee), providing him with an understanding of Trustmark’s credit culture and philosophy, which is a skill essential to the Board’s risk oversight function. He is a member of the National Association of Corporate Directors.

1415

		Augustus L. Collins, 6566 Director of Trustmark since 2020 (Independent Director)   Trustmark Corporation Committees: ·   Audit ·   Enterprise Risk ·   Human Resources		Career Highlights: ·   CEO, MINACT Inc. (Job Training, Development and Management)   Other Public Company Boards: ·   Huntington Ingalls Industries ·   Mississippi Power Company

Experience and qualifications:General Collins has served as the CEO of MINACT Inc., a job training, development and management company, since 2016. He retired with the rank of Major General in the Mississippi National Guard, having served as Adjutant General of both the Mississippi Army National Guard and the Mississippi Air National Guard from 2012 to 2016. His 35 years of combined military service in the U.S. Army and the Mississippi National Guard included the command of the 155th Brigade Combat Team in Iraq, where he was responsible for security operations in the southern and western provinces. He was previously appointed by the Governor to the Mississippi Workers’ Compensation Commission where he served as the commission’s representative of labor. General Collins’ years of service and leadership provide him with valuable experience in strategic and financial planning as well as human resources. He is a member of the National Association of Corporate Directors.

Experience and qualifications: Mrs. Conerly is a certified public accountant and a former certified valuation analyst. Her experience as a former partner at a large certified public accounting firm has provided her with significant financial and accounting expertise, particularly in the areas of auditing, business valuation and tax, and qualifies her for service as one of the Board’s audit committee financial experts. Mrs. Conerly’s years of service as a director of a publicly-traded financial institution provide her with valuable experience in financial institution governance and an understanding of markets that are a strategic focus for Trustmark. Mrs. Conerly also served on the Bank Board’s Asset/Liability Committee (the responsibilities of which are now performed by the Finance Committee), providing her with an understanding of Trustmark’s balance sheet strategy, which is a skill essential to the Board’s risk oversight function. She is a member of the National Association of Corporate Directors.

1516

Experience and qualifications: Mr. Dewey became president and chief executive officer of Trustmark and the Bank on January 1, 2021. He was formerly president and chief operating officer of the Bank from January 1, 2020, to December 31, 2020. He served as chief operating officer of the Bank from January 1, 2019, to December 31, 2019, and as President of Corporate Banking from 2008 to 2018. Mr. Dewey, with 1920 years of experience at Trustmark and 3738 years in the financial services industry, has worked in diverse geographic markets and in numerous lines of banking businesses. His executive management responsibilities in retail and institutional banking, mortgage, wealth management and insurance services enable him to provide valuable operational, strategic and financial perspectives to the Board. Mr. Dewey is a member of the National Association of Corporate Directors.

Experience and qualifications: Mr. Eduardo has served as the Dean of the School of Business at a private college in Mississippi since 2003. He holds Ph.D. (Finance) and MBA degrees and serves as the Anderson Distinguished Professor of Finance at Mississippi College. Mr. Eduardo, an accomplished academic, has authored numerous articles on a variety of topics, including investment management, compliance, capital management and the pricing of retail banking services, which have been published in national and international journals. His expertise in banking and corporate finance, combined with his proven marketing and leadership skills, provide valuable marketing, strategic and financial perspectives to the Board, and qualifies him for service as one of the Board’s audit committee financial experts. Mr. Eduardo also served as Chair of the Bank Board’s Asset/Liability Committee (the responsibilities of which are now performed by the Finance Committee). He is a member of the National Association of Corporate Directors.

1617

		J. Clay Hays, Jr., M.D., 5758 Director of Trustmark since 2017 (Independent Director)   Trustmark Corporation Committees: ·   Enterprise Risk (Chair) ·   Executive ·   Nominating & Governance		Career Highlights: ·   Cardiologist, Partner, President, Jackson Heart Clinic, PA

Experience and qualifications: Dr. Hays is president of Jackson Heart Clinic, PA, one of the largest cardiology groups in Mississippi. He is a former chairman of the Mississippi Healthcare Solutions Institute and former director and past president of the Mississippi State Medical Association. He serves as director and secretary of the Medical Assurance Company of Mississippi, a statewide medical malpractice insurer. He is also a Mississippi Delegate to the American Medical Association House of Delegates and Chair Elect of the Southeast Delegation of the AMA House of Delegates. With extensive experience in the medical industry, Dr. Hays is uniquely positioned to advise Trustmark on the healthcare industry. Dr. Hays also served on the Bank Board’s Asset/Liability Committee (the responsibilities of which are now performed by the Finance Committee). He is a member of the National Association of Corporate Directors.

Experience and qualifications: Mr. Host has served as Chair of Trustmark and the Bank since April 2022. He served as Executive Chairman of Trustmark and the Bank from January 1, 2021 to April 26, 2022. Mr. Host served as president and chief executive officer of Trustmark and chief executive officer of the Bank from January 1, 2011, to December 31, 2020, and served as president of the Bank from 2011 to December 31, 2019. He also served as a director of the Federal Reserve Bank of Atlanta from 2012 until the end of his second term on December 31, 2018. Throughout his 38-year tenure with Trustmark, Mr. Host has served in a variety of executive management capacities, including chief financial officer, chief investment officer and president of various divisions. Mr. Host’s in-depth knowledge of Trustmark’s operations and of the financial services industry enables him to provide both historical and strategic perspectives in Board discussions regarding corporate strategy and governance matters. He is a member of the National Association of Corporate Directors.

1718

		Harris V. Morrissette, 6364 Director of Trustmark since 2016 (Independent Director)   Trustmark Corporation Committees: ·   Enterprise Risk ·   Finance ·   Human Resources		Career Highlights: ·   President, China Doll Rice & Beans, Inc. (Regional Packaged and Food Services CompanyCompany)) ·   Former President and CEO, Marshall Biscuit Company, Inc.   Other Directorships: ·   Williamsburg Investment Trust

Experience and qualifications: Mr. Morrissette serves as the president of a regional packaged food and food services company based in Alabama. His prior years of service as a director of a publicly-traded financial institution provide him with valuable experience in financial institution governance and an understanding of markets that are a strategic focus for Trustmark. In addition, Mr. Morrissette’s background and business acumen provide him with the skills necessary to contribute invaluable insight and broad perspectives to Board discussions. He also served on the Bank Board’s Credit Policy Committee (the responsibilities of which are now performed by the Enterprise Risk Committee). Mr. Morrissette is a member of the National Association of Corporate Directors.

		Richard H. Puckett, 6869 Director of Trustmark since 1995 Lead Director of Trustmark since 2020 (Independent Director)   Trustmark Corporation Committees: ·   Executive (Chair/Lead Director) ·   Human Resources ·   Nominating & Governance (Chair/Lead Director)		Career Highlights: ·   Chairman and CEO, Puckett Machinery Company (Distributor of Heavy Earth Moving Equipment and Engine Power Systems)

Experience and qualifications: Mr. Puckett is the chairman and chief executive officer of a heavy equipment distribution and rental company with facilities located in Mississippi and eastern Louisiana that provide heavy equipment, engine power solutions and related supplies to a variety of industries. Mr. Puckett brings marketing and business leadership skills to the Board, as well as an in-depth understanding of the business climate and customer base in Trustmark’s major legacy markets. His experience and Board tenure provided valuable perspective to his service on the Bank Board’s Credit Policy Committee (the responsibilities of which are now performed by the Enterprise Risk Committee). Mr. Puckett is a member of the National Association of Corporate Directors.

Experience and qualifications: Mr. Yates is the president and chief executive officer of a commercial construction company with operating divisions located throughout the Southeast, many of which are within markets served by Trustmark. Mr. Yates’ knowledge of these markets, as well as his leadership experience in the various aspects of the construction industry, including employee relations matters, contract negotiations, and risk management, provide the Board with an important resource for assessing and managing risks and planning for corporate strategy. He formerly served as a member of the Bank Board’s Asset/Liability Committee and Credit Policy Committee (the responsibilities of which are now performed by the Finance Committee and the Enterprise Risk Committee, respectively). In January 2021, Mr. Yates was appointed a director of the Federal Reserve Bank of Atlanta, New Orleans Branch. In addition, he serves as a director and is former chairman of the Mississippi Economic Council. Mr. Yates is a member of the National Association of Corporate Directors.

��

18

19

EXECUTIVE COMPENSATION

Compensation Discussion and Analysis

Guiding Philosophy.The guiding philosophy of the Human Resources Committee of the Board (the Committee) is to attract and retain highly qualified executives and to motivate them to maximize shareholder value while managing risk appropriately and maintaining the safety and soundness of the organization. The Committee believes that executive compensation should be linked to Trustmark’s performance and significantly aligned with both the short-term and long-term interests of Trustmark’s shareholders. The Committee also believes that executive compensation should be designed to allow Trustmark to recruit, retain and motivate employees who play a significant role in the organization’s current and future success. Further, compensation policies and practices should be designed to help develop management talent, promote teamwork among, and high morale with, executive management, establish effective corporate governance, and set compensation at competitive levels.

Trustmark’s compensation policies reflect the Committee’s guiding philosophy, as shown below:

What we don’t do:

No automatic or guaranteed annual salary increases

 

No guaranteed bonuses or guaranteed long-term incentive awards

 

No tax gross-ups for executive officers

 

No “single-trigger” change in control severance payments

 

No hedging of Trustmark stock

 

No excessive perquisites

Key Elements of Compensation.The following table summarizes key elements of Trustmark’s executive compensation program and the primary objectives each element supports. The Committee believes these elements are standard compensation components for named executive officers (NEOs) at Trustmark’s peer companies:

1920

Alignment Between Pay and Performance.Trustmark is committed to aligning the compensation of its executive officers with Trustmark’s financial and operational performance. The Committee believes that its current executive compensation program is helping to achieve these goals by aligning compensation with Trustmark’s performance. Key financial and core operating results for 20222023 included the following:

ReturnThe Committee uses both annual cash bonuses and equity awards to link executive pay with Trustmark’s performance. Payouts under the annual management incentive plan are based on Trustmark’s achievement of key corporate, strategic and line of business performance goals. A minimum achievement of the threshold is required to earn the minimum annual cash bonus, and Trustmark performance that exceeds the target results in higher bonus awards. In 2023, Trustmark’s performance resulted in average payouts for the NEOs under the annual management incentive plan of 127.95% of target, out of a maximum potential payout of 200%. In recent years, cash bonuses under the annual management incentive plan have averaged approximately 35% of the CEO’s and 32.25% of the other NEOs’ total annual compensation.

Total equity awards granted in 2023 represent approximately 33% of the CEO’s, and 26% of the other NEOs’, total annual compensation. Performance-based equity awards granted in 2023, which represented approximately 17% (for the CEO) and 13% (for the other NEOs) of each NEO’s total annual compensation, will be earned based on Trustmark’s achievement of return on average tangible equity (ROATE), compared to an absolute target level, and total shareholder return (TSR), which includes dividends, compared to Trustmark’s peer group, in each case over a three-year performance period. The performance-based equity awards granted in 2021 were earned based on Trustmark’s achievement of ROATE compared to an absolute target level and TSR, which includes dividends, compared to Trustmark’s peer group, in each case over a three-year performance period. Trustmark’s performance over the three years ended December 31, 2023, resulted in combined vesting achieved for the performance-based restricted stock awards granted in 2021 of 120.5%.

ROATE is a non-GAAP financial measure, but does not have a comparable GAAP financial measure. Return on average tangible equity is calculated using net income adjusted for intangible amortization divided by total average tangible common equity (total shareholders’ equity less goodwill and other identifiable intangible assets); it excludes the impact of (i) restructurings, discontinued operations, extraordinary items and other significant non-routine transactions, (ii) material litigation and insurance settlements, (iii) changes to comply with ASU 2016-02 and ASU 2016-13, and (iv) cumulative effects of income tax and accounting changes in accordance with US GAAP.

The Committee uses both annual cash bonuses and equity awards to link executive pay with Trustmark’s performance. Payouts under the annual management incentive plan are based on Trustmark’s achievement of key corporate, strategic and line of business performance goals. A minimum achievement of the threshold is required to earn the minimum annual cash bonus, and Trustmark performance that exceeds the target results in higher bonus awards. In 2022, Trustmark’s performance resulted in average payouts for the NEOs under the annual management incentive plan of 160.0% of target, out of a maximum potential payout of 200%. In recent years, cash bonuses under the annual management incentive plan have averaged approximately 37.0% of the CEO’s and 33.3% of the other NEOs’ total annual compensation.

Total equity awards granted in 2022 represent approximately 31% for the CEO’s, and 25% for the other NEOs’, total annual compensation. Performance-based equity awards granted in 2022, which represented approximately 16% (for the CEO) and 13% (for the other NEOs) of each NEO’s total annual compensation, will be earned based on Trustmark’s achievement of return on average tangible equity (ROATE), compared to an absolute target level, and total shareholder return (TSR), which includes dividends, compared to Trustmark’s peer group, in each case over a three-year performance period. The performance-based equity awards granted in 2020 were earned based on Trustmark’s achievement of ROATE compared to an absolute target level and TSR, which includes dividends, compared to Trustmark’s peer group, in each case over a three-year performance period. Trustmark’s performance over the three years ended December 31, 2022, resulted in combined vesting achieved for the performance-based restricted stock awards granted in 2020 of 94.75%.

Time-based equity awards, which in 20222023 represented approximately 16%17% of total annual compensation (for the CEO) and 13% (for the other NEOs), further encourage a focus on long-term growth and financial success by aligning the interests of management and Trustmark’s shareholders.

As a result of the structure of Trustmark’s annual management incentive plan and its performance-based equity awards, the Committee believes that compensation awarded to its NEOs is effectively aligned with Trustmark’s performance. Average payouts of annual cash bonuses under the management incentive plan of 158.7%144.9% of the target amount for each of the NEOs for the past three years relates directly to Trustmark’s achievement with respect to corporate and line of business budget targets for those years. Vesting of the performance-based equity awards of 94.75%120.5%, 42.2%94.75% and 93.5%42.2% for the three years ended December 31, 2023, 2022 2021 and 2020,2021, respectively, reflects how the amount of this incentive compensation earned depends on Trustmark’s performance, including compared to its peer companies.

20222023 Say on Pay Vote.In 2022,2023, the advisory shareholder vote on Trustmark’s executive compensation received approval of over 97.3%96.1% of the votes cast on the proposal. In light of such strong support, during the remainder of 20222023 and in 2023,2024, the

21

Committee has continued to apply the same compensation philosophy that was described in the 20222023 proxy statement in determining amounts and types of executive compensation.

20

Trustmark’s peer group, as reviewed by the Committee in February 2022,2023, consisted of 20 peer companies, all of which had assets within a range of approximately 68% to 208%221% of Trustmark’s asset size, which the Committee considers an appropriate

21

value of which varies with changes in Trustmark’s stock price. The equity awards percentage in the above calculations were valued as of the grant date based on the fair market value of the underlying stock. Other benefits, including Trustmark’s allocations and contributions to benefit plans and perquisites, are not considered in the above calculations. For more information on these benefits, please see “All Other Compensation for 2022”2023” table on page 31.32.

22

The following table shows the threshold, target and potential maximum bonus payout levels established for each NEO under the management incentive plan, expressed as a percentage of base salary, for 2022:2023:

Depending on achievement against the stated goals, the payout percentage, if any, for 20222023 could range from a level of 50% of the target bonus payout (for threshold performance achievement) to a level of 100% (for target performance achievement) to a level of 200% (for maximum performance achievement). If performance is below the threshold level for each of an NEO’s goals under the management incentive plan, no bonus is earned under the plan absent exercise of discretion by the Committee.

For 2022,2023, overall incentive targets for NEOs were allocated among a corporate performance goal and corporate strategic operational drivers. The following table shows the weightings of these goals for each NEO for 2022:2023:

For 2022,2023, the threshold and maximum performance levels continue to reflect the uncertainty of achieving the goals and provide variability in pay for changes in performance while also requiring high performance to reach the maximum payout level. For the 20222023 bonus matrix, the Committee recommended, and the Board approved, the following threshold and maximum performance levels for the NEOs: