Our annual meeting of stockholders will be held at our office at 1750 Presidents Street, Reston, Virginia, on Friday, April 28, 2023, at 9:00 a.m. Eastern Time and at any and all adjournments, postponements or continuations of the meeting. Due to space limitations, attendance is limited to stockholders, and one guest each. Admission to the meeting is on a first-come, first-served basis. Registration will begin at 8:00 a.m. Eastern Time. Valid government-issued picture identification and proof of stock ownership as of the record date must be presented to attend the meeting. If you hold shares of Leidos common stock through a broker, bank, trust or other nominee, you must bring a copy of a statement reflecting your stock ownership as of the record date, follow the instructions provided by them in order to attend the annual meeting of stockholders, and you must present a legal proxy from your bank, broker, trust or other nominee in order to vote. Cameras, recording devices and other large electronic devices, such as tablets or laptops, as well as backpacks, or other large bags or packages are not permitted in the meeting. If you require special assistance at the meeting because of a disability, please contact the Corporate Secretary at 1750 President Street, Reston, VA 20190. For additional information regarding our annual meeting, see our proxy statement available below.

Friday, April 28, 2023 at 9:00 a.m. ET

To cast your vote before the meeting, please visit www.proxyvote.com and follow the on-screen instructions. You will be prompted to enter the control number located on the front of your notice or proxy card to access this voting site.