Daniel Louis "Dan" Castellaneta is an American actor, voice actor, comedian and screenwriter. Noted for his long-running role as Homer Simpson on the animated television series The Simpsons, he voices many other characters on The Simpsons, including Abraham "Grampa" Simpson, Barney Gumble, Krusty the Clown, Groundskeeper Willie, Mayor Quimby and Hans Moleman.
Born in Oak Park, Illinois, a suburb of Chicago, Castellaneta started taking acting classes at a young age. He would listen to his father's comedy records and do impressions of the artists. After graduating from Northern Illinois University, Castellaneta joined Chicago's Second City in 1983, and performed with the troupe until 1987. He was cast in The Tracey Ullman Show, which debuted in 1987. The Tracey Ullman Show included a series of animated shorts about a dysfunctional family. Voices were needed for the shorts, so the producers decided to ask Castellaneta to voice Homer. His voice for the character started out as a loose impression of Walter Matthau, but later evolved into a more robust voice. The shorts would eventually be spun off into The Simpsons.