Johnny Whitaker began his professional acting career at the age of three by appearing in a television commercial for a local used car dealer. In 1965, Whitaker originated the character of the young Scotty Baldwin in the soap opera General Hospital. In 1966, he acted in a major feature film, The Russians Are Coming, the Russians Are Coming, which also starred Brian Keith, the actor who would later play Whitaker’s uncle in the television series Family Affair.
Family Affair aired from 1966 to 1971. It co-starred Whitaker playing the role of an orphaned boy named Jody Davis, living in a high-rise apartment in New York City. While a regular on the show, Whitaker also starred in the Hallmark Hall of Fame production The Littlest Angel and an episode of the long-running western The Virginian in 1969. His most prominent feature film role was the lead in the musical version of Tom Sawyer (1973).