USS Artemis (AKA-21) was an Artemis-class attack cargo ship in service with the United States Navy from 1944 to 1947.

After fitting out at Boston, Mass., the attack cargo ship proceeded to the Chesapeake Bay for shakedown training.

On 13 November, the ship arrived at Port Hueneme to take on pontoon equipment and carried this cargo to Pearl Harbor.

The vessel got underway on 12 January with units of Task Force (TF) 51 for amphibious training exercises off Maui and arrived back at Pearl Harbor on the 18th.

Steaming via Saipan, the ship anchored in Transport Area "Baker" off the southeast coast of Iwo Jima on 19 February.

She unloaded at Manila in mid-July before proceeding to Tacloban, Philippine Islands, to pick up troops and equipment for transportation to Hawaii.

Upon her arrival at Samar, Artemis embarked military personnel for transport back to the United States.

Upon her arrival at Pearl Harbor, the ship conducted logistic support operations for nearby naval activities until 15 May, when she was assigned to Joint Task Force 1 to support "Operation Crossroads," tests conducted at Bikini Atoll to learn of the effects of atomic bomb explosions upon warships.

This assignment occupied the cargo ship through mid-August when she returned to Pearl Harbor and resumed local operations.

The ship was transferred to the Maritime Administration on 1 April 1948 and was laid up in the National Defense Reserve Fleet in the James River.