William Paul Petersen (born September 23, 1945 in Glendale, California) is an American movie actor, singer, novelist, and activist for child stars.

Paul Petersen started out in show business at the age of ten when he became a "Mousketeer" on the Mickey Mouse Club. However, he achieved stardom as a teenage heartthrob on The Donna Reed Show, an ABC family sitcom that ran from 1958 to 1966. Petersen's fame brought recording offers and although his singing voice was limited, he had hit record singles with songs such as My Dad, She Can't Find Her Keys, Amy, and Lollipops and Roses that made it into the Billboard Hot 100.

Difficult times followed his almost instantaneous disappearance from the Hollywood spotlight. As a result, Petersen returned to university and obtained a degree in literature that helped him to go on to write sixteen adventure novels. In 1990, he founded a child-actor support group.