Dan Castellaneta ( born October 29, 1957) is an American actor, voice actor, comedian and screenwriter. Castellaneta is best known for voicing Homer Simpson on the animated series The Simpsons (as well as other characters on the show such as Abraham "Grampa" Simpson, Barney Gumble, Krusty the Clown, Sideshow Mel, Groundskeeper Willie, Mayor Quimby, and Hans Moleman). Castellaneta also had voice roles in several other programs, including Futurama, Sibs and Darkwing Duck, The Adventures of Dynamo Duck, The Batman, Back to the Future: The Animated Series, Aladdin, Taz-Mania Animaniacs and Hey Arnold! He also occasionally guest starred on shows like Friends and How I Met Your Mother.