Apollo was laid down under a United States Maritime Commission contract, MC hull 860, on 24 June 1943 at Pascagoula, Mississippi, by the Ingalls Shipbuilding Corporation; launched on 6 November 1943; sponsored by Mrs. James B. Hill; and acquired by the Navy and placed in reduced commission on 31 December 1943 for passage to her conversion yard.

The vessel proceeded to the Atlantic Basin Iron Works, Brooklyn, New York, and was decommissioned there on 14 January 1944 to undergo conversion for naval service as a submarine tender.

[1] After loading stores, the new submarine tender got underway for shakedown in the waters off New London, Connecticut, and in Block Island Sound.

[1] Apollo transited the Panama Canal on 13 November; paused briefly at San Diego, California, for replenishment; and continued on to Pearl Harbor, Hawaii.

Upon reaching that port on the 8th, the tender took up the task of placing submarines of the New London Group, 16th Fleet, in an inactive status.