USS Celtic (AF-2) was an Celtic-class stores ship acquired by the U.S. Navy for use in the Spanish–American War. She served again during World War I in the dangerous North Atlantic Ocean, delivering general goods and ammunition to American Expeditionary Force troops in Europe.
Celtic (AF-2) was built in 1891 by Workman, Clark and Co., Ltd., Belfast, Northern Ireland, as SS Celtic King; purchased by the Navy 14 May 1898; fitted out at New York Navy Yard; and commissioned 27 May 1898, Lieutenant Commander N. J. K. Patch in command.
From 11 June to 25 September 1898, Celtic supplied fleet units in Cuban and Florida waters with medical supplies, fresh provisions, and ice. On 12 October, she cleared New York to round Cape Horn on the long route to the Asiatic Station, arriving at Cavite, Philippine Islands, 30 March, for service as storeship. Supporting the quelling of the Philippine–American War, Celtic carried stores and passengers between the Philippines and Australian ports until 16 July 1903, when she weighed anchor for Puget Sound Navy Yard. Here she was out of commission between 18 September 1903 and 19 October 1905.
Returning to New York City 24 January 1906, Celtic began supply operations with the Atlantic fleet until 23 February 1907, when she again went out of commission. She was recommissioned at Boston Navy Yard 23 October 1908. At the suggestion of her commander, President Roosevelt ordered the Celtic to earthquake-damaged Sicily because she was already full of Christmas provisions, where she set up a tent city at Messina. She returned to her U.S. East Coast and Caribbean operations 15 April 1909. Key supply ship for the Veracruz operation, Celtic lay anchored off the Mexican city from 16 June 1914 to 24 July 1915, except for occasional voyages to Key West, Florida, and Cape Haitien, Haiti, for replenishment.