Bleloch was the son of the geologist, William Edwin Bleloch.[3] Bleloch matriculated at St. Andrew's College, Grahamstown and enrolled at the University of the Witwatersrand where he was awarded a B.Sc. degree with first-class honours in 1927, and an M.Sc. degree in 1928. From there he studied at the University of London, and obtained a Ph.D. in chemical engineering, with first-class honours in chemistry, in 1930. While in London he met a young American, Jean Denny, whom he subsequently married.