VMF-113 was activated on 1 January 1943 at Marine Corps Air Station El Toro as part of Marine Base Defense Air Group 41. They were soon given their full complement of 24 F4U Corsairs. On 26 March 1944, while escorting four B-25 bombers on a raid over Ponape, they recorded their first enemy kills, downing eight Japanese aircraft. In April of that year, VMF-113 was tasked with providing air support for the landings at Ujelang. Since the assault was unopposed, the squadron quickly returned to striking Japanese targets in the Marshall Islands for the remainder of 1944.