Fulton was first married to actress Ethel Scott, who appeared with him on "The Rikki Fulton Show" in 1960 and 1961. While separated from their respective partners, Fulton met Audrey Matheson Craig-Brown (known as Kate Matheson), an actress 13 years his junior. Matheson saw Fulton perform in a production of Noël Coward's "Hay Fever", but it would be 17 years before they met in person. After one day together, Fulton proposed and they married in 1969. In 1976, Matheson became pregnant but later lost the baby.