Quinn’s first wife was actress Katherine DeMille, the adopted daughter of Cecil B. DeMille; they wed in 1937. The couple had five children: Christopher (1938–1941), Christina (born December 1, 1941), Catalina (born November 21, 1942), Duncan (born August 4, 1945), and Valentina (born December 26, 1952). Their first child, Christopher, aged two, drowned in the lily pond of next-door neighbor W. C. Fields.In 1965, Quinn and DeMille divorced because of his affair with Italian costume designer Jolanda Addolori (died 2016), whom he married in 1966. They had three children: Francesco Quinn (March 22, 1963 – August 5, 2011), Danny Quinn (born April 16, 1964), and Lorenzo Quinn (born May 7, 1966).