The Virginia native, who was raised on a tobacco farm, began his career as a child performer, appearing in stage musicals like "Li'l Abner" and "The Music Man". He broke into stand-up comedy soon after completing his courses at Emerson College. After appearing in New York at such famed spots as Catch a Rising Star, The Improv and Caroline's, he was slotted by MTV into a "5 Funny Guys" special in 1989. Appearances on "The Comedy Club Network" and on various programs on The Nashville Network followed. In 1995, Clark was the hit of the "Young Comedians Show" on HBO, hosted by Garry Shandling. By then, Clark had also appeared as a gas station attendant in the 1990 award-winning Broadway production of "The Grapes of Wrath", starring Gary Sinise and Lois Smith, a role he reprised for the 1991 "American Playhouse" (PBS) production. He also appeared in a recurring role on ABC's "Ellen" (1995-96), before snagging his own sitcom.

Clark's feature film work has been slower in happening. He had his debut in "Dogfight" (1991), as a marine, co-starring River Phoenix. He reteamed with Phoenix and Sandra Bullock in Peter Bogdanovich's "The Thing Called Love" (1993), in which Clark played a country comedian amongst aspiring country-western singers. He also was cast in the abominably stereotypical gay barber who cleaned up Sean Connery in Michael Bay's "The Rock" (1996).

Following the demise of "Boston Common", Clark could often be found in comedy clubs honing new material. He also returned to the genre in 1997 when he joined the ABC series "Soul Man" as a bumbling, overeager, recently graduated divinity student who often was at odds with Dan Aykroyd's free spirited pastor. Clark made a third attempt at series stardom as a first-time parent juggling the demands of career with his desire to help his wife with their baby in "Yes, Dear" (CBS, 2000- ).