Buenos Aires was a merchant ship requisitioned for use as a transport by the Spanish Navy in June and July 1898 during the Spanish–American War.

[1] Serving as a transport, she became part of the relief expedition for the Philippines commanded by Rear Admiral Manuel de Camara and charged with destroying the United States Navy Asiatic Squadron of Commodore George Dewey there, as well as with delivering 4,000 Spanish Army troops to reinforce the Philippines.

[2] Camara's squadron—consisting of battleship Pelayo, armored cruiser Emperador Carlos V, auxiliary cruisers Patriota and Rapido, destroyers Audaz, Osado, and Proserpina, and transports Panay, Alfonso XII, and Antonio Lopez, and four colliers as well as Buenos Aires—sortied from Cadiz on 16 June 1898.

[6] By the time Buenos Aires and the rest of Camara's squadron arrived at Suez on 5 July 1898,[7] the squadron of Vice Admiral Pascual Cervera y Topete had been annihilated in the Battle of Santiago de Cuba, freeing up the U.S. Navy's heavy forces from the blockade of Santiago de Cuba.

[8] Buenos Aires and the rest of the squadron departed Suez on 11 July 1898 for Spain.