Geraldine Leigh Chaplin was born on July 31, 1944, in Santa Monica, California, the fourth child of actor and filmmaker Charlie Chaplin, and the first child of his fourth wife, Oona O'Neill, whom he married in 1943. Charlie Chaplin was 55 when Geraldine Chaplin was born and Oona was 19 years old. Chaplin was the first of their eight children. Her paternal grandparents were English Charles Chaplin Sr. and Hannah Chaplin (born Hannah Harriet Pedlingham Hill), and her maternal grandparents were Nobel- and Pulitzer-Prize-winning American playwright Eugene O'Neill and English-born writer Agnes Boulton.