William Adger Moffett (31 October 1869 – 4 April 1933) was an American admiral and Medal of Honor recipient known as the architect of naval aviation in the United States Navy.

He was the son of George Hall Moffett (1829–1875), who enlisted in the Confederate States army as a private, and was promoted for bravery on the field of battle, eventually attaining the rank of Captain and adjutant-general, Hagood's Brigade, Twenty-fifth South Carolina Volunteers.

A master politician, he maintained official support for naval aviation against Billy Mitchell, who favored putting all military aircraft into a separate air force.

Moffett was a strong advocate of the development of lighter-than-air craft, and lost his life when the USS Akron, then the largest dirigible in the world, crashed in the Atlantic Ocean during a storm off the coast of New Jersey on 4 April 1933.

Moffett brought his ship into the inner harbor during the nights of the 21st and 22d without the assistance of a pilot or navigational lights, and was in a position on the morning of the 22d to use his guns at a critical time with telling effect.