The Bureau of Aeronautics (BuAer) was the U.S. Navy's material-support organization for Naval Aviation from 1921 to 1959. The bureau had "cognizance" (i.e., responsibility) for the design, procurement, and support of Naval aircraft and related systems. Aerial weapons, however, were under the cognizance of the Navy's Bureau of Ordnance (BuOrd).

Congress established BuAer in 1921 in order to create a single organizational home for Naval Aviation. Prior to 1921, cognizance for aviation had been divided among various Navy bureaus and other organizations. The first Chief of BuAer was Rear Admiral William A. Moffett (1869–1933), a Medal of Honor recipient and battleship commander who had long supported the development of Naval Aviation. He served as bureau chief from 1921 until his death in 1933, in the crash of the airship USS Akron (ZRS-4).

A talented administrator, Moffett ensured the continued independence of Naval Aviation during the 1920's, when Army Brig. Gen. William "Billy" Mitchell and others sought to merge all U.S. military aviation into a single, independent air force. Upon Moffett's death, he was succeeded as Chief, BuAer, by Rear Admiral Ernest J. King--a future Fleet Admiral and Chief of Naval Operations during World War II. Other important bureau chiefs included Rear Admiral John S. McCain, Sr., the grandfather of U.S. Senator John S. McCain III (R-Ariz.).