William Alexander Young MB, CHB, DPH, DTM (5 November 1889 – 28 May 1928) was a Scottish doctor and surgeon who specialised in tropical medicine. He spent most of his career in West Africa, as a pathologist and bacteriologist with the West African Medical Service, where he studied many of the endemic diseases. The majority of his research was carried out in Nigeria and later at Accra, Gold Coast (modern-day Ghana). He is remembered particularly as having done much to further the understanding of the nature and epidemiology of yellow fever. He died aged 38 of yellow fever, during the course of his research.