 Mosley was born on 16 November 1896 at 47 Hill Street, Mayfair, Westminster.He was the eldest of the three sons of Sir Oswald Mosley, 5th Baronet (1873–1928), and Katharine Maud Edwards-Heathcote (1874–1950), daughter of Captain Justinian H. Edwards-Heathcote of Apedale Hall, Staffordshire.He had two younger brothers