SS Mission San Juan was a Type T2-SE-A2 tanker built for the United States Maritime Commission during World War II. After the war she was acquired by the United States Navy as USS Mission San Juan. Later the tanker transferred to the Military Sea Transportation Service as USNS Mission San Juan. She was a member of the Mission Buenaventura-class oiler and was named for Mission San Juan Bautista in San Juan Bautista, California.