USS Galatea was a large steamer acquired by the Union Navy during the American Civil War.

Based at Cap-Haïtien in Haiti, where she arrived 29 February, she provided convoy protection in the West Indies to California mail steamers plying between New York City and Aspinwall, United States of Colombia.

She had twice returned to New York City for repairs by 10 November 1864 when she was assigned with two other ships to convoy California mail streamers from Cap-Haïtien through the Windward Passage, between the islands of Nacassa and Mariguana.

Remaining on station at Cape Haitien, she cruised to Key West, Florida, for provisions and dispatches and afforded protection to American citizens in Haiti until convoy service was discontinued in June 1865.

Renamed Alexandre Pétion, on 20 September 1868, she attacked the rebel ships Liberté and Sylvain at Petit-Goâve.