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,

2025 was an outstanding year for Leidos fueled by operational excellence and a strategy aligned to customer priorities. Despite the complexities of DOGE and the longest U.S. government shutdown in history, we prosecuted the year with a productive sense of urgency across our portfolio and delivered on our promises. We grew revenue by 3 percent to a record $17.2 billion and delivered strong bottom line profitability and cash flow. Our book-to-bill ratio exceeded 1.0, and our wins included multiple large-scale awards across our most competitive markets, including takeaways and franchise extensions. These outcomes contributed to a total shareholder return that meaningfully outperformed our peer set.

Our 2025 results reflect the clarity and discipline we established under our new NorthStar 2030 growth strategy. NorthStar 2030 is the product of our year of deep strategic thinking in 2024, during which we assessed our portfolio and market positioning against long-term customer demand and national priorities. It now serves as a durable operating system for Leidos, focusing us on five carefully selected Growth Pillars where customer demand is expanding, market economics are attractive, and Leidos differentiation is clear and accelerating. Just as importantly, it provides a disciplined framework for capital allocation and organizational alignment.

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.”

The benefits of this strategic clarity became increasingly evident during 2025 as the new U.S. administration shifted government priorities, heightened scrutiny of federal spending, and increased emphasis on efficiency and measurable outcomes. Against the backdrop of those dynamics, Leidos remained focused on disciplined execution and leaned into our new strategy, outsmarting complex challenges and outdoing competitors. And we earned continued customer trust by remaining anchored in our purpose ofmaking customer outcomes smarter and more efficient.

We also took decisive portfolio actions to accelerate our NorthStar 2030 Growth Pillars. We acquired Kudu Dynamics, bringing exquisite capabilities to our Cyber Growth Pillar. That acquisition is already performing exceptionally well, generating rapid growth, providing entry into new markets, and sustaining robust profitability. We also aligned our Energy business for our Energy Infrastructure Growth Pillar. We divested Varec, a non-core legacy energy asset. And we announced the planned acquisition of ENTRUST Solutions Group, a premier power and utilities engineering and design firm with a consistent track record of growth and strong profitability. When this transaction closes in the first half of 2026, Leidos will be a $1.3 billion Utility Engineering and Power design business with a clear path toward significant revenue and profitability expansion. These actions, and those that will follow, set the stage for the next phase of accelerated and sustainable growth for our company.

None of this progress would be possible without the 47,000 Leidos teammates around the world who bring our bold vision to life each day. Their dedication and relentless pursuit of excellence on behalf of our customers enables superior performance even in the most dynamic times. We continue to invest in their growth through competitive benefits, expanded technical upskilling, and leadership development.

For 2026, I am confident that the traction from our NorthStar 2030 strategy will become even more evident. Our business and balance sheet are strong. Our portfolio is aligned to customer priorities. And our culture is grounded in keeping our promises. On behalf of our leadership team, Board of Directors, and the entire Leidos workforce, thank you for your continued trust and investment in Leidos. I invite you to review the accompanying Proxy Statement and vote in accordance with the Board’s recommendations.

THOMAS A. BELL

Chief Executive Officer

Letter from the Independent Chair

DEAR FELLOW STOCKHOLDERS,

On behalf of your Board of Directors, thank you for your continued investment and engagement with Leidos. As our CEO describes in his letter, Leidos demonstrated strong execution in 2025 amid significant external complexity. The Board’s focus was clear throughout: maintain rigorous oversight, support disciplined execution, and safeguard long-term value creation. The record financial results and shareholder returns that management delivered reflect the strength of our strategy, the quality of our portfolio, and the dedication of our workforce.

The Board’s central priority in 2025 was ensuring that our NorthStar 2030 strategy translated into durable operating discipline and tangible outcomes. We devoted meaningful agenda time to reviewing growth pillars, portfolio positioning, and enterprise-level risk, with particular attention to evolving Administration priorities and procurement dynamics. We sought clear milestones, consistent accountability, and strategic technology investments, and we encouraged management to convert strategic momentum into durable margin, cash generation, and high-quality bookings. The Board is encouraged by the evidence of traction across the portfolio and remains committed to sustaining robust oversight and operating cadence.

Capital deployment oversight was another area of sustained Board focus. In 2025, we emphasized investments that enhance our operational readiness, deepen our technical talent, and expand the capabilities our customers rely on. We reviewed management’s cost actions aimed at preserving margins amid procurement delays, pricing pressures, and payment timing changes tied to the operating environment. Throughout these deliberations, our objective remained constant: deploy capital in ways that strengthen program execution and position Leidos to meet the demands of an evolving national security landscape.

We remain steadfast in our commitment to rigorous oversight, transparent engagement, and disciplined capital allocation in service of long-term stockholder value.”

The Board also oversaw decisive portfolio shaping aligned to NorthStar 2030, assessing strategic fit, valuation discipline, integration readiness, and risk-adjusted returns for each inorganic opportunity. Risk oversight remained equally foundational, with the Board and its committees maintaining active oversight of cybersecurity, artificial intelligence, regulatory changes, and compliance.

Strong governance supported these efforts. We maintained our established best practices, including regular independent executive sessions, robust committee structures, and annual Board evaluations, while continuing to prioritize composition and refreshment. Following the 2025 annual meeting, our Board consists of ten directors, nine of whom are independent, with an independent, non‑executive Chair. We thank our recently retired directors for their dedicated service and impact.

The Board also devoted considerable time to human capital and oversaw constructive engagement with stockholders on strategy, governance, and workforce matters. We reviewed culture, leadership development, and workforce initiatives designed to support execution of NorthStar 2030 and to strengthen our position as an employer of choice. We appreciate the dedication and professionalism our colleagues bring to the mission every day, and we value the perspectives our stockholders shared with us throughout the year.

Looking ahead, your Board is confident in Leidos’ trajectory for 2026 and NorthStar 2030, and we remain steadfast in our commitment to rigorous oversight, transparent engagement, and disciplined capital allocation in service of long‑term stockholder value. We invite you to review the accompanying Proxy Statement and to vote in accordance with the Board’s recommendations. Thank you for your trust and continued investment in Leidos.

Sincerely,

ROBERT S. SHAPARD

Independent 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 1, 2026. 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 proxy statement. 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.