Sir James Young Simpson, 1st Baronet, FRSE FRCPE FSA Scot (7 June 1811 – 6 May 1870), was a Scottish obstetrician and a significant figure in the history of medicine. He was the first physician to demonstrate the anaesthetic properties of chloroform on humans and helped to popularise its use in medicine.
Simpson's intellectual interests ranged from archaeology to an almost taboo subject at the time: hermaphroditism. He was an early advocate of the use of midwives in the hospital environment. Many prominent women also consulted him for their gynaecological problems. Simpson wrote Homœopathy, its Tenets and Tendencies refuting the ideas put forward by Hahnemann.
His services as an early founder of gynaecology and proponent of hospital reform were rewarded with a knighthood and by 1847 he had been appointed as physician to the Queen in Scotland.