Byers, Sir John William (1852/3–1920), obstetrician and folklore scholar, was the only child of the Rev. John Byers and Margaret Byers (qv) (née Morrow), presbyterian missionaries to China, and was born in Shanghai. His father was already seriously ill, and died (1853) on the journey home to Ireland; Margaret Byers took up a teaching position in Cookstown, Co. Tyrone, and moved (1859) to Belfast, where she founded a girls' school later known as Victoria College. John Byers attended Royal Belfast Academical Institution and QCB, graduating in arts with a gold medal and first-class honours in both BA (1874) and MA (1875) degrees of the QUI, and also with honours in the MD degree of the RUI (1878); he was awarded an honorary master of obstetrics degree by the latter body. He undertook further medical studies in Dublin and London, and took up a post in 1879 in the Belfast Children's Hospital; in 1882 he set up a department of women's diseases in the Royal Victoria Hospital, and from 1893 to 1920 was professor of midwifery and of the diseases of women and children in QCB (later QUB). He was noted as a skilled physician and teacher, was consultant to several Belfast hospitals, and published a good deal, particularly on the treatment of disorders and complications of pregnancy and labour, such as puerperal fever and eclampsia.
He held office in a number of local and national medical societies, and was a fellow of the Royal Society of Medicine, a council member (1902–6) of the British Medical Association, and first chairman of the Irish committee of the BMA; he was involved in planning the Maternity Hospital and the Royal Victoria Hospital in Belfast. He helped bring about the changes in medical training and in midwifery that were made necessary by new legislation and the reorganisation of higher education, and was knighted (1906) in recognition of his public work. He was also interested in Ulster dialect, literature, and folklore, and may have understood Irish; he published more than twenty pamphlets and articles on these subjects, and was president of the Belfast Literary Society twice (1885–6, 1915–16) and also of the Belfast Natural History and Philosophical Society (1908–11). Byers died in Belfast on 20 September 1920.
He married (10 September 1902) Fanny Reid of Belfast; they had three sons.