Oscar M. Westover (July 23, 1883 – September 21, 1938) was a major general and fourth chief of the United States Army Air Corps.

In 1919, Lieutenant Colonel Westover was detailed to the United States Army Air Service to serve as Assistant Executive Officer for Director Major General Charles T. Menoher, where he butted heads with Billy Mitchell over subordination to authority, and on July 1, 1920, transferred permanently to the new Air Service branch with the rank of major.

On December 22, 1935, he succeeded Benjamin Foulois as Chief of the Air Corps with the accompanying promotion to major general.

GHQ Air Force, activated with about 8000 soldiers was considered the equivalent of an infantry or cavalry division and was accordingly commanded by a major general.

GHQ Air Force was commanded by Major General Frank M. Andrews, a classmate of Westover's who had finished one place higher in class standings.

The Northrop A-17AS he flew, a single-engined attack aircraft used as a high-speed staff transport, had a reputation for stalling, and only a year before Colonel William McChord had been killed in the crash of one.

[3] Westover was succeeded by the Assistant Chief of Air Corps, Brigadier General Henry H. Arnold on September 29.