Giacomo Signori (11 June 1914 – 5 February 2005) was an Italian swimmer and water polo player.
He won two medals at the 1934 European Aquatics Championships, and at least seven national titles in freestyle swimming events.As a water polo player, he won three national titles with the Rari Nantes Florentia (1934), Canottieri Olona (1947), and Rari Nantes Camogli (1953) teams.
After retiring from competitions, he worked as a swimming coach.