Young was born in Eastleigh, Hampshire, the third of four children of Edwin Young (1878–1936), a builder and contractor, and his wife Gertrude Mary (née Brown; 1880–1945). He went to school in Southsea from 1912 to 1915 and then Portsmouth Grammar School from 1915 to 1924. He was not very good at school, but liked the Officers' Training Corps; later he returned to present prizes and told the pupils that his parents would have been very surprised to see him in the hall on speech day because he had never come close to winning any school award.