Born June 5, 1974 in Cerritos, California, Chad Allen, whose full name is Chad Allen Lazzari, grew up in Long Beach, CA. He's the youngest of four boys, and his parents were hoping for a girl. They got one, in the shape of Chad's twin sister, Charity. Chad was the "extra change", as he puts it.
 
Chad got his start in show business when his mother started entering him and his twin sister Charity in "twin contests" at fairs, and they won quite a few times. People kept telling his mother how cute the twins looked together, and that she should try to get the them into acting.
 
Charity didn't much like show business at all, but Chad was bitten by the acting bug. It was decided that Chad Lazzari sounded like a name for a dark-haired Italian, not a blond, blue-eyed boy, and he started out on his acting career as Chad Allen instead. His first job was in a McDonalds television commercial, at age four. His first dramatic work came at age six, in a pilot for a television series that never went into production, Cutter to Houston.
 
His first big break in a television series happened when he was eight and joined the cast of "St. Elsewhere" as Tommy Westphall, an autistic boy. He played that character literally until the very end, when he was the last actor on-screen in the final scene of the final episode of St. Elsewhere in 1988. During that period, he worked continuously (and sometimes simultaneously) on a succession of other successful TV shows: Webster (1985-1986), Our House (1986-1988) and My Two Dads (1989-1990).
 
Chad filled his "spare time" by guest-starring in a whole host of other television shows, such as Airwolf, Hunter, The Wonder Years, Star Trek The Next Generation, In the Heat of the Night, Highway to Heaven, Simon and Simon, and appeared in ten television movies. He also appeared in several stage productions, as a guest on TV game shows and in a series of public service anti-drug programs.