USAF usually refers to the United States Air Force, the aerial warfare branch of the U.S. Armed Forces.
USAF may also refer to: United States Armed Forces itself, the military of the United States of America United Student Aid Funds, a nonprofit corporation that works to enhance postsecondary-education preparedness, access and success Upper Saint Anthony Falls, part of the Saint Anthony Falls Jane's USAF, a 1999 video game A common typo for UASF or "User Activated Soft Fork", a technique for updating Bitcoin and other blockchains
See also USSF (disambiguation) U.S.A.A.F. - United States Army Air Force