Keesler Air Force Base (IATA: BIX, ICAO: KBIX, FAA LID: BIX) is a United States Air Force base located in Biloxi, a city along the Gulf Coast in Harrison County, Mississippi, United States. The base is named in honor of aviator 2d Lt Samuel Reeves Keesler Jr., a Mississippi native killed in France during the First World War. The base is home of Headquarters, Second Air Force (2 AF) and the 81st Training Wing (81 TW) of the Air Education and Training Command (AETC).

The base has specialized in ground trade training since its opening in 1941 during World War II. It has had high-quality technical schools and absorbed units moved from other bases under the Base Realignment and Closure Act (BRAC).