John Gilchrist (February 5, 1792 – September 15, 1859) was a physician and political figure in Canada West.
He was born in Bedford, New Hampshire in 1792 and studied at the medical school at Yale College and Dartmouth College. He apprenticed as a physician in Goffstown, New Hampshire and came to Hamilton Township in Upper Canada around 1817. He was licensed to practice medicine in 1819; he set up practice first at Cobourg and later Peterborough. Gilchrist served as surgeon for the local militia. He moved to Otonabee Township, where he set up a sawmill and gristmill on the Indian River with Zacheus Burnham and later opened a general store and distillery. The settlement of Gilchrist’s Mills (later Keene) developed around these mills. He served as a director of the Cobourg Harbour Company and as chairman of the building committee for the Upper Canada Academy at Cobourg. He was elected to the Legislative Assembly of Upper Canada in 1834 for Northumberland County and, in 1841, he was elected to the Legislative Assembly of the Province of Canada in the North riding of Northumberland. He served as a district agent for the Crown Lands Department and was treasurer for Colborne District from 1842 to 1845. In 1849, he moved to Port Hope and continued to practice medicine until his death in 1859.