D'Abo was born on 22 January 1969 in London, England, the daughter of Maggie London, an English model and Actress, and Mike d'Abo, an English singer and member of 1960s group Manfred Mann. She has an older brother, as well as two half-brothers and one half-sister: elder brother Ben, younger half-brother Bruno, and younger sibling twins Ella and Louis (born July 2007) on her father's side. Olivia and Ben both attended high school in the US at Los Feliz Hills School (formerly "The Apple School") in Los Angeles and d'Abo attended Pacoima Junior High School in Pacoima, California.