He is perhaps best known for playing Henry Jefferson on All in the Family and section chief Billy Melrose on the television series Scarecrow and Mrs. King.

In the early 1960s, he appeared in the Broadway shows Purlie Victorious, The Hostage, The Cool World and Simply Heavenly.

Stewart played roles in various television series including That Girl, Marcus Welby, M.D., The Bob Newhart Show, Good Times and Harry O.

Stewart starred on Scarecrow and Mrs. King as section chief Billy Melrose during the show's four-year run from 1983 through 1987, and continued guest-starring in both television and films.

[1] A third degree black belt in aikido, Stewart opened a dojo for inner-city youth in the Bayview district of San Francisco.