Women dated: Ann Todd (1930), Merle Oberon (1930), Carole Lombard (1930), Wendy Barrie (1935), Viginia Bruce (1937), Norma Shearer (1939), Primula Rollo (1940-46), Hjordis Tersmeden (1948-83), Paulette Goddard (1950), Grace Kelly (1955), Marlene Dietrich (1956), Ginger Rogers (1957), Deborah Kerr, Evelyn Keyes, Hedy Lamarr, Doris Duke, Margot Fonteyn, Loretta Young, Mae West, Rita Hayworth, Ava Gardner, Marilyn Monroe, Princess Margaret
David Niven played Bond in the comedy Casino Royale in 1967. The movie is a footnote to the proper Bond canon, and was also not very funny. Niven, though, was a funny chap—a happy-go-lucky, extremely popular Englishman in Hollywood. A review of a biography in the New York Times describes Niven as "a world-class swordsman" who is said to have bagged "Merle Oberon, whom he almost married, Rita Hayworth, Ava Gardner, Marilyn Monroe and, possibly, Grace Kelly and Princess Margaret."
Those substantial charms, apparently, wore off pretty quickly with wife Hjordis Tersmeden, by the way. Their 35-year marriage was by most accounts totally miserable.