Geraldine Chaplin was born in Santa Monica, California, the first child of actor/director Charlie Chaplin and Oona O'Neill (daughter of playwright Eugene O'Neill and author Agnes Boulton). She was educated at a boarding school in Switzerland where she became fluent in French and Spanish, the former being standard in any Swiss school and the latter being demonstrated in some of her performances in films by the Spanish director Carlos Saura, her former husband, with whom she had a twelve-year relationship.

Geraldine married a long time companion, Chilean cinematographer Patricio Castilla, in 2006 and has two children, Shane (b. 1974, by Saura) and Oona (b. 1986, by Castilla). Chaplin is also the half sister of Sydney Chaplin, Charles Chaplin, Jr. and Norman Chaplin. Geraldine lives much of her time in Miami, Florida at home next to the beach.