Lorenzo Marcello (Venice, 1603 – Dardanelles, 26 June 1656) was a Venetian admiral.
He fought against the Papal navy in 1642-1644 and subsequently participated in the new Turkish-Venetian War. In September 1655, he succeeded Francesco Morosini as the Captain General of the Sea. From this position he led the combined Venetian-Maltese fleet in battle in the Dardanelles in June 1656. Although he himself lost his life during the battle, it resulted in the greatest Venetian victory since the Battle of Lepanto.
The name Lorenzo Marcello has been given to two Italian ships: a liner (1,413 grt, 234 ft. long) built in the 1920s and sunk in 1943, and a Marcello-class submarine, launched on 20 November 1937 and sunk on 22 February 1941.