 Clarke was born in Sydney, New South Wales, the son of Rupert Clarke, 2nd Baronet (a prominent pastoralist and Member of Parliament) and Elsie Tucker (born in Melbourne).His father purchased the Villa Les Abeilles in Monte Carlo and the young Rupert attended a French-speaking primary school.Upon his father's death on Christmas Day 1926, he succeeded as the 3rd Baronet of Rupertswood when he was only seven years old.