USS Bellatrix (AK-20) was a United States Navy cargo ship and the name ship of her class. Tampa Shipbuilding built her, and she was launched on 15 August 1941.
The Navy commissioned Bellatrix on 17 February 1942. She entered service under the cargo-ship designation AK-20.
On 7 August 1942 she took part in the landings on Guadalcanal and Tulagi. That day she was a cargo ship in Transport Division A, with Fuller and American Legion, off Beach Red. William Francis Dietrich was in command. On 1 February 1943 the Navy reclassified her AKA-3. She survived the war. Bellatrix was decommissioned on 1 April 1946. The Navy recommissioned her on 16 May 1952.