The IV Fighter Command is a disbanded United States Air Force unit. It was activated under Fourth Air Force at March Field, California in June 1941, when it replaced a provisional organization. It was responsible for training fighter units and for the air defense of the southern portion of the Pacific Coast. Following the attack on Pearl Harbor, the command's units were placed on alert. In 1942, its air defense responsibility was expanded to include the entire Pacific coast of the continental United States and the command moved its headquarters from southern California to Oakland Airport, California, which was more centrally located. As the threat to the Pacific decreased, it was disbanded on 31 March 1944.