Leidos Holdings, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934 (Amendment No. )

Leidos Holdings, Inc.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Letter to Our Stockholders

DEAR FELLOW STOCKHOLDERS,Thanks to the dedication of our 48,000 teammates worldwide, I am proud to report that Leidos achieved outstanding success throughout fiscal year 2024. Not only did we increase revenues by 7.9% to a record $16.7 billion and deliver strong bottom line and cash performance, but we also exceeded the ambitious three-year financial goals we set in 2021. On top of that, 2024 was our best growth year since 2020, with an overall book-to-bill ratio of 1.4 and year-over-year backlog growth of 18% to $43.6 billion. This excellent multi-year performance now gives us the financial flexibility to deploy capital in support of our growth initiatives and shareholder value going forward. Building on our 2024 momentum, we expect 2025 to be another exciting year as we implement our new NorthStar 2030 growth strategy, the outcome of the year of deep strategic thinking which I foreshadowed in my previous letter. Grounded in careful evaluation of our portfolio against our 10-year Leidos Proprietary Hypothesis of the Future, our strategy keys on a select group of specific “growth pillars” where we know customer needs are growing, market profitability is robust, and Leidos differentiation is evident and accelerating. The new U.S. administration’s emphasis on driving efficiency across government operations only increases our confidence in our new strategy. The domestic and geopolitical megatrends that we predicted would occur over the next decade are now coming true at an even faster pace than expected. And because of our work last year, we are well prepared. NorthStar 2030 positions us well now, and in the future, because it is grounded in one unifying theme: Leidos exists to make our customer outcomes smarter and more efficient. Everything we do—for every one of our customers—is linked to this statement. Leidos was created to leverage innovation for our customers to meet the immense and enduring national security challenges faced by America and its allies—whether it be deterring and winning battles abroad, protecting the homeland, or driving government efficiencies to expand economic strength and fuel the future. That is exactly what the new U.S. administration is focused on, too. We view its priorities as tremendous opportunities for Leidos, and we are moving at pace to seed the field with ideas for better, faster, and cheaper government solutions, underpinned by our Promises Made, Promises Kept culture and Making Smart Smarter mindset. As always, we recognize that our people are the driving force behind our success. That is why we have made significant investments to enhance employee benefits, expand technical upskilling initiatives, and raise our stature as an employer of choice where the best and brightest can Break Limits throughout their careers. By supporting employee growth, we strengthen our ability to deliver smarter digital and mission innovations to our customers.

“These are exciting times indeed. With our NorthStar 2030 strategy to guide us, I am confident that our past success is just prologue to an awesome future ahead.”

LETTER TO OUR STOCKHOLDERS

These are exciting times indeed. With our NorthStar 2030 strategy to guide us, I am confident that our past success is just prologue to an awesome future ahead. For now, I invite you to carefully review the attached Proxy Statement and vote in a way that supports the continued success of Leidos, in line with our Board’s recommendations.On behalf of our Leidos teammates, our leadership team, and our Board of Directors, thank you for your trust and investment in Leidos. Your unwavering support fuels our drive and our success—for that, I am deeply grateful.THOMAS A. BELLChief Executive Officer

Letter to Our Stockholders

DEAR FELLOW STOCKHOLDERS,The Leidos Board of Directors greatly appreciates your ongoing investment and interest in our Company. We are incredibly proud of our team’s dedication to our mission of serving government and commercial customers with smarter, more efficient digital and mission innovations. In fiscal 2024, we achieved exceptional financial performance, including a revenue growth of 8% and an increase in non-GAAP earnings per share of 40%. We also increased our quarterly dividend and continued our share repurchase program, returning a total of $906 million to our stockholders. These results reflect the steadfast commitment of our 48,000 employees toward our goals and sustainable growth strategy, as well as the trust our customers place in us. Thank you for being an integral part of our journey.As your Board of Directors, we remain committed to maintaining strong governance practices and upholding our core values of integrity, innovation, agility, collaboration, commitment, and inclusion. We have maintained active oversight of the business, ensuring that our strategic objectives are met and that we continue to deliver value to our stockholders. With the addition of a new member over the past year and the retirement of three esteemed members, the Board will consist of nine independent members plus Tom Bell, the Leidos CEO, after the annual meeting. Our Board encompasses a mix of fresh perspectives and seasoned experience. This diversity equips us to navigate risks and seize strategic opportunities in an evolving world.We are pleased to welcome Tina W. Jonas to our Board. Tina brings a wealth of experience from both government and private sectors. As the former Undersecretary of Defense (Comptroller) of the Department of Defense, she managed one of the world’s largest budgets, overseeing over $400 billion in defense spending annually. Her strategic financial management and commitment to fiscal responsibility significantly support operational efficiency and accountability. Tina’s expertise in financial management, risk assessment, and strategic planning will be invaluable to Leidos as we continue to grow and navigate an increasingly complex global environment.We would like to take a moment to honor the outstanding contributions of our retiring members.Bob Kovarik has been instrumental in strengthening our financial oversight and governance. With exceptional expertise in finance and auditing, Bob has significantly enhanced the integrity and transparency of our financial practices. His deep understanding of risk management and analytical prowess has ensured that Leidos maintains the highest standards of financial integrity. Bob’s commitment to excellence and his ability to navigate complex financial landscapes have contributed immensely to our sustainable growth.

“We remain committed to maintaining strong governance practices and upholding our core values of integrity, innovation, agility, collaboration, commitment, and inclusion. We have maintained active oversight of the business, ensuring that our strategic objectives are met and that we continue to deliver value to our stockholders.”

LETTER TO OUR STOCKHOLDERS

Surya Mohapatra has provided invaluable insights through his visionary leadership and profound knowledge of the healthcare industry. His strategic acumen and innovative thinking have been catalysts for our growth strategies and innovation initiatives. Surya’s dedication to advancing healthcare technology and improving patient outcomes has expanded our impact in this critical sector. His perspectives on industry trends and technological advancements have been a driving force in our pursuit of excellence and leadership in innovation.Susan Stalnecker has offered exceptional guidance rooted in her deep expertise in corporate governance and risk management. Her strategic mindset, financial acumen, and commitment to ethical business practices along with her adeptness at navigating complex organizational challenges have strengthened our Company’s foundation. Her insightful perspectives and unwavering dedication have greatly enhanced our Board's effectiveness and have been instrumental in steering Leidos toward continued success.In 2024, the Company and the Board engaged in a year of deep strategic thinking, actively discussing the Company's future strategy and providing guidance and oversight. We will share these developments with our stockholders at our Investor Day. The Board is enthusiastic about our NorthStar 2030 strategy, which paints a bold vision of who we aim to be, guiding us like the steadfast North Star. Under Tom Bell’s leadership as our Chief Executive Officer, we believe Leidos will continue to thrive, and we are confident that Tom’s guidance will drive us toward sustained success.We remain committed to proactive engagement with our stockholders. Throughout fiscal 2024, senior management engaged with shareholders who collectively own the majority of our shares. Our discussions covered various topics, from board composition and human capital management to supply chain and corporate strategy. The feedback we received has been instrumental in shaping our practices and focusing our attention on critical issues.We deeply appreciate the trust you have placed in us and your continued investment in Leidos’ future. It is our privilege to serve you and Leidos in our roles as directors. Sincerely,ROBERT S. SHAPARDIndependent Chair

Notice of Annual Meeting of Stockholders

If you hold your shares of Leidos common stock in street name, you should follow any instructions provided by your broker, bank, trust, or other nominee.

Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting of Stockholders to be held on May 2, 2025. The proxy statement and the annual report are available atwww.proxyvote.com.

Table of Contents

Certain statements in this proxy statement and letters to our stockholders, other than purely historical information, including estimates, projections, statements relating to our business plans, objectives and expected operating results, and the assumptions upon which those statements are based, are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Forward-looking statements may appear throughout this report. These forward-looking statements generally are identified by the words “believe,” “project,” “expect,” “anticipate,” “estimate,” “intend,” “strategy,” “future,” “opportunity,” “plan,” “may,” “should,” “will,” “would,” “will be,” “will continue,” “will likely result,” and similar expressions. Forward-looking statements are based on current expectations and assumptions that are subject to risks and uncertainties which may cause actual results to differ materially from the forward-looking statements. We undertake no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events, or otherwise.