Luca Marin (born 9 April 1986 in Vittoria, Province of Ragusa) is a former Italian medley swimmer. He specialized in the 400 m medley, and won ten medals at European and World Championships in this event. At the 2006 European Short Course Swimming Championships he won a gold medal, beating László Cseh, the world record holder. At the top of his career, he was trained by the Albanian coach Gjon Shyti.
He participated at the 2004 Summer Olympics at Athens for Italy, reaching 10th place in the 400 m medley. At the 2008 Summer Olympics he finished in 5th place in the same event, and 12th at the 2012 Summer Olympics.
Luca Marin was engaged to Laure Manaudou and Federica Pellegrini.