Francis Butler Loomis Jr. (June 21, 1903 – December 31, 1989) was a decorated officer of the United States Marine Corps, who reached the rank of major general. He is most noted as executive officer of the 1st Defense Battalion during the Shelling of Johnston and Palmyra and later as Logistic Officer of III Marine Amphibious Corps during Battle of Okinawa. He was the son of United States Assistant Secretary of State, Francis B. Loomis.