From 1962-1965, he had a relationship with Natalie Wood.
In between this relationship, Warren was also seeing Claudia Cardinale (1963). From 1967 to 1974, Julie Christie was his sweetheart.
She was married to actor Robert Wagner, to producer Richard Gregson, and then back to Wagner.
She had one daughter with Gregson, actress Natasha Gregson Wagner.
Warren was dating Michelle Phillips from 1973 to 1976. 1979 to 1981, Warren was having an affair with Bitten Knudson.
That she thought the way she did about me and took the time with me meant everything in the world," Wagner said. When they divorced, his career got a boost with a role in The Pink Panther before he moved to television to star in It Takes a Thief, Switch and Hart to Hart.Warren dated Isabelle Adjani (1986-1987) while in 1988 Joyce Hyser was his girlfriend. He also had relationships with female celebrities Connie Chung, Judy Carne, Bebe Buell, Stacey Nelkin, Dayle Haddon, Cynthia Sikes, Jennifer Lee Pryor, Dewi Sukarno, Diana Ross, Margaux Hemingway, Brooke Hayward, Jeanne Rainer, Diane von Furstenberg, Raquel Welch, Candice Bergen, Tsipi Levine, Elle Macpherson, Mamie Van Doren, Alexandra Stewart, and Charlene Gehm. This was said to have continued till Warren met actress Annette Bening. He cast her in the movie Bugsy and later married her in 1992.The couple shares four children together; Stephen, Benjamin, Isabel, and Ella.July 20, 1938 – November 29, 1981) was an American actress.She began her career in film as a child and became a successful Hollywood star as a young adult, receiving three Academy Award nominations before she turned 25 years old.