Parfit was born in 1942 in Chengdu, China, the son of Jessie (née Browne) and Norman Parfit, medical doctors who had moved to Western China to teach preventive medicine in missionary hospitals. The family returned to the United Kingdom about a year after Parfit was born, settling in Oxford. Parfit was educated at Eton College, where he was nearly always at the top of the regular rankings in every subject except maths. From an early age, he endeavoured to become a poet, but he gave up poetry towards the end of his adolescence.