Paul Edward Valentine Giamatti (pronounced /dʒiəˈmɑːti/; born June 6, 1967) is an American actor. Giamatti began his career as a supporting actor in several commercially successful and critically acclaimed films produced during the 1990s including Private Parts, The Truman Show, Saving Private Ryan, The Negotiator, and Man on the Moon, before earning lead roles in several projects in the 2000s including American Splendor, Sideways, Cinderella Man, The Illusionist, John Adams, Cold Souls, and Barney's Version.
Giamatti was born in New Haven, Connecticut. His father, Angelo Bartlett Giamatti, was a Yale University professor who later became president of the university and commissioner of Major League Baseball. His mother, Toni Marilyn (née Smith), was a homemaker and English teacher who taught at Hopkins School and had also previously acted. Giamatti's mother was of Irish descent; his paternal grandfather, Valentine Giamatti, was the son of Italian immigrants from Telese, and his paternal grandmother, Mary Claybaugh Walton, was from a New England family.
Giamatti is the youngest of three children. His brother, Marcus, is also an actor, and his sister, Elena, is a jewelry designer. He was educated at The Foote School and graduated from Choate Rosemary Hall in 1985. He attended Yale University, where he was elected to the Skull and Bones secret society.