On television, Campbell became known to viewers when he co-starred with
John Ritter on the short-lived ''
Three's Company spin-off Three's a Crowd'' (1984–1985) in which he played the comedic role of E.Z. Taylor, Jack Tripper's "surfer dude" assistant chef at his bistro. He also co-starred for five seasons with
William Conrad and
Joe Penny as Assistant District Attorney Derek Mitchell on the
CBS crime drama
Jake and the Fatman (1987–1992). Campbell has guest starred on numerous television shows including
The Facts of Life,
Matlock,
All My Children,
Law & Order,
Law & Order: SVU,
Homicide: Life on the Street, as well as the
web series,
Submissions Only and
Then We Got Help!. Campbell was also an established stage actor having appeared on
Broadway,
Off-Broadway and
regional theater. In 1994, he made his Broadway debut in the New York premiere of
Andrew Lloyd Webber's musical
Sunset Boulevard starring opposite
Glenn Close and
Alice Ripley, and received a
Best Actor in a Musical Tony Award nomination for his performance as Joe Gillis, a role he reprised from the musical's 1993 US premiere in Los Angeles starring opposite Close, again, and
Judy Kuhn. He also starred in
Susan Stroman's 2000 Tony Award-winning musical
Contact at the
Vivian Beaumont Theater,
Lincoln Center, and its final performance was broadcast by
PBS as part of its
Live from Lincoln Center series on September 1, 2002. His most current Broadway role was playing Sam Carmichael in the hit musical
Mamma Mia! from 2014 until production ceased in September 2015. His Off-Broadway credits include
Adrift In Macao,
Book of Days,
Avow and
Hello Again. He has appeared in several regional theatrical productions of
Race,
Death and the Maiden,
12 Angry Men,
Hay Fever,
Of Thee I Sing,
Oleanna,
Beauty and the Beast,
Johnny Guitar,
Bells Are Ringing,
On Shiloh Hill,
Boogie Woogie Rumble of a Dream Deferred and ''
Breakfast at Tiffany's, and productions of I Love My Wife and The Nerd''. ==Personal life==