Giamatti ( ) is an American surname, a variant of Italian Giammattei (). The surname is derived from the given name Gian Matteo, from Italian forms for 'John' and 'Matthew'. Notable people with the surname include: A. Bartlett Giamatti (1938–1989), President of Yale University and later Commissioner of Major League Baseball Marcus Giamatti (born 1961), American actor, son of Bart and brother of Paul Paul Giamatti (born 1967), American actor, son of Bart References Italian-language surnames