John Brown (1735-1788), Scottish physician, was born in 1735 at Lintlaws or at Preston, Berwickshire. After attending the parish school at Duns, he went to Edinburgh and entered the divinity classes at the university, supporting himself by private tuition. In 1759 he seems to have discontinued his theological studies, and to have begun the study of medicine. He soon attracted the notice of William Cullen, who engaged him as private tutor to his family, and treated him in some respects as an assistant professor. In time, however, he quarrelled with Cullen, as with the professors of the university in general, and from about 1778 his public lectures contained vigorous attacks on all preceding systems of medicine and Cullen's in particular. In 1780 he published his Elementa Medicinae, expounding his own, or as it was then called the Brunonian, theory of medicine, which for a time had a great vogue. In 1786 he set out for London in the vain hope of bettering his fortunes, and died there of apoplexy on the 17th of October 1788.

An edition of his works, with notice of his life by his son, William Cullen Brown, appeared in 1804.