American Dad!: Cast American Dad! Comedy, Family 2/6/05 – 3/7/22 United States http://www.tbs.com/shows/american-dad.html GeneralEpisodesCastCharactersGallery Cast See full cast → Scott Grimes as Steve Smith Dee Bradley Baker as Klaus Heissler Seth MacFarlane as Stan Smith Roger Greg Corbin Patrick Stewart as Avery Bullock Kevin Michael Richardson as Principal Brian Lewis