Several ships of the Argentine Navy have been named ARA San Luis (or San Luis before the 1860s):
San Luis (1814), a felucca that served in the second Argentine squadron during the Independence War
ARA San Luis (1912), a destroyer originally ordered by Argentina that was purchased by Greece (as Aetos) in 1912 before delivery
ARA San Luis (D-10), a Buenos Aires-class destroyer, in service with Argentina 1938 to 1971
ARA San Luis (S-32), a Type-209 submarine in service with Argentina from 1974 to 1997