Sir James Young Simpson (7 June 1811 – 6 May 1870) was a Scottish doctor and an important figure in the history of medicine. Simpson discovered the anaesthetic properties of chloroform and successfully introduced it for general medical use.

James Simpson was born in Bathgate, West Lothian the youngest of eight children, Thomas, John, Alexander, David, George (died young), George and a sister Mary. His parents were Mary Jarvey (also known as Jarvie) and David Simpson, a baker in Bathgate. James received his initial education at the local school, but because of his obvious abilities his father and brothers (his mother died when he was 9) together paid for a College education and he entered the University of Edinburgh when he was 14 years old. He became a Licentiate in 1830 before graduating in 1832. He was appointed Professor of Midwifery (which would now be called Obstetrics) at the University of Edinburgh and physician to Queen Victoria.

Simpson's name at birth was "James Simpson", as recorded at his baptism on 30 June. It is unknown why he formally adopted the middle name "Young". One theory is that, as a very young professor, he was flaunting his youth in front of his older peers or alternatively that he was known by the affectionate nickname of "Young Simpson" and decided to incorporate it into his name.