Prof James Gregory FRSE FRCPE (January 1753 – 2 April 1821) was a Scottish physician and classicist.
He was the eldest son of John Gregory (1724–1773) and Elizabeth Forbes (died 1761), and was born in Aberdeen. He was educated at Aberdeen Grammar School, King's College, University of Aberdeen, the University of Edinburgh (MD 1774), the University of Oxford, and Leyden University.
He accompanied his family moving to Edinburgh in 1764, and after going through the usual course of literary studies at that university, he was for a short time a student at Christ Church, Oxford. It was there probably that he acquired that taste for classical learning which afterwards distinguished him. He studied medicine at Edinburgh, and, after graduating doctor of medicine in 1774, spent the greater part of the next two years in Leiden, Paris, and in Italy.
Shortly after his return to Scotland he was appointed in 1776 to the chair his father had formerly held, and in the following year he also entered on the duties of teacher of clinical medicine in the Edinburgh Royal Infirmary.
In 1783 Gregory was one of the founders of the Royal Society of Edinburgh.
On the illness of William Cullen in 1790 he was appointed joint-professor of the practice of medicine, and he became the head of the School of Medicine at the University of Edinburgh on the death of Dr. Cullen in the same year.