Keith was born near Aberdeen on 6 November 1752, and died at Tulliallan, Clackmannanshire on 7 March 1823. His family were a minor branch of the Keiths who held the title Earl Marischal. Keith was educated privately and then at Marischal College, Aberdeen, graduating BA in 1770 and later receiving a doctorate in divinity in 1803. He was licensed by the presbytery of Aberdeen in 1774 and then was presented to the living of Keith-Hall and Kinkell, Aberdeen after some confusion owing to the simultaneous presentation of another candidate by the Earl Marischal himself, then living in Potsdam, Keith's position was finally confirmed in 1778. In 1822 he was translated to Tulliallan, where he remained until his death.
From The Biographical Dictionary of British Economists in Oxford Reference.