USS Catalpa (1864) was a steamer acquired by the Union Navy during the American Civil War. She was used by the Navy for various purposes, but especially to patrol navigable waterways of the Confederacy to prevent the South from trading with other countries. Catalpa, a screw tugboat, was built in Brooklyn, New York, in 1864 as Conqueror; purchased by the Navy 29 June 1864; commissioned 12 July 1864, Acting Ensign J. A. Edgren in command; and reported to the South Atlantic Blockading Squadron.