Skandar Keynes was born in London, 5 September 1991, the son of Zelfa Cecil Hourani and author Randal Keynes. His maternal grandfather, Cecil Fadlo Hourani, was a former adviser to the late Tunisian president Habib Bourguiba, as well as a famous cook. Through his father, Keynes is the great-great-great grandson of the famous biologist Charles Darwin, through whom he is descended from Thomas Howard, 3rd Duke of York (uncle to both Queen Anne Boleyn and Queen Catherine Howard), thus making him distantly related to Queen Elizabeth I and King Edward I. He has an older sister, Soumaya Keynes.