He was the son of Sir Hugh Foot (who was the last Governor of Cyprus and Jamaica and, as Lord Caradon, the Permanent Representative of the United Kingdom to the United Nations from 1964 to 1970) and the grandson of Isaac Foot, who had been a Liberal MP. He was a nephew of Michael Foot, later leader of the Labour Party, with whom the younger Foot was close. He spent his youth at his uncle's house in Devon, in Italy with his grandmother and with his parents (who lived abroad) in Cyprus and Jamaica.