Armour Residential REIT, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

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ARMOUR RESIDENTIAL REIT, INC.

Telephone: (772) 617-4340

Dear Stockholder:

ARMOUR Residential REIT, Inc., cordially invites you to attend the 2025 annual meeting of stockholders. We will hold the meeting on Thursday, May 1, 2025, virtually beginning at 8:00 a.m. (EDT). You or your proxy holder may participate and vote virtually, by visitingwww.virtualshareholdermeeting.com/ARR2025 and entering the control number on the proxy card or notice of the meeting you received. You are not required to register before the meeting starts. We hope that you will be able to participate. Your feedback and your vote are very important to us.

Whether or not you plan to participate in the meeting, your shares should be represented and voted. After reading the accompanying proxy statement, please vote your shares as soon as possible. Stockholders may vote by Internet, by phone, or by completing and mailing a proxy card if one has been requested. Stockholders may also vote on the annual meeting website during the meeting, as further explained in the proxy statement. Submitting a vote before the meeting will not preclude you from updating your vote on-line during the virtual meeting. In addition, this proxy statement, the notice of annual meeting, the proxy card and our 2024 annual report will be made accessible via the Internet on the Company’s website atwww.armourreit.com and atwww.virtualshareholdermeeting.com/ARR2025, or mailed, if requested, on or about March 20, 2025.

We look forward to the opportunity to interact with stockholders at the 2025 annual meeting.

On behalf of our Board of Directors, I extend our appreciation for your continued support.

Sincerely,

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