Speed 14 k
Armament 4 3"
Orion (AC-11) was laid down by the Maryland Steel Co. Sparrows Point, Md., 6 October 1911, launched 23 March 1912, and commissioned at Norfolk 29 July 1912.
Assigned to general collier duty with the Atlantic Fleet in September, Orion remained in the western Atlantic until placed in reserve at Norfolk 9 October 1914. Recommissioned 28 December 1914 she continued to serve the Atlantic Fleet until ordered to Cavite in January 1917.
At Colon in the Canal Zone when the United States entered World War I, Orion remained there until 21 May, then returned to Norfolk, whence she steamed to the Azores for operations during June and July. During the latter month she also assisted in placing a defensive chain across the harbor at Punta Delgado. Returning briefly to Hampton Roads Orion departed again 18 August and carried coal and drafts of men to Bahia, Brazil for further transfer to Frederick, Mount Baker, and Glacier. During the fall she served on the east coast from Norfolk to Boston, then, in January 1918, joined the Naval Overseas Transport Service.
Continuing her collier duties under NOTS, she served on general duty in Chesapeake Bay until she steamed south again in April. In May she off loaded coal at Montevideo, then headed back toward New York. Just after departing the former she sighted an enemy submarine and fired on it, chasing it off. On arrival back in the United States she resumed her more mundane coastal collier duties.
After the end of the war and the completion of a coal run to France, Orion returned to the United States and on 5 February 1919 was detached from NOTS and assigned to duty with the Atlantic Fleet. In June she steamed to the west coast where she joined the Pacific Fleet and for the next year resupplied ports on the west coasts of both North and South America. In August she was transferred to the Naval Transport Service, then on maneuvers in the West Indies, and with that service continued to supply fleet units until December 1925. Then ordered inactivated, she decommissioned at Norfolk 18 June 1926. Struck from the Navy List 10 July 1931 she was sold to the Union Ship Building Co., Baltimore, Md. 30 August 1933.