William Cullen FRS FRSE FRCPE FPSG was a Scottish physician, chemist and agriculturalist, and one of the most important professors at the Edinburgh Medical School during its heyday as the leading centre of medical education in the English-speaking world.
Cullen was also a central figure in the Scottish Enlightenment. He was David Hume's physician and friend, and on intimate terms with Adam Smith, Lord Kames (with whom he discussed theoretical and practical aspects of husbandry), Joseph Black, John Millar, and Adam Ferguson, among others.
He was President of the Royal College of Physicians and Surgeons of Glasgow (1746 – 47), President of the Royal College of Physicians of Edinburgh (1773 – 1775) and First Physician to the King in Scotland (1773 – 1790). He was also, incidentally, one of the prime movers in obtaining a royal charter for the Philosophical Society of Edinburgh, resulting in the formation of the Royal Society of Edinburgh in 1783.