John Barclay (1734-1798), Scottish divine, was born in Perthshire and died at Edinburgh. He graduated at St Andrews, and after being licensed became assistant to the parish minister of Errol in Perthshire. Owing to differences with the minister, he left in 1763 and was appointed assistant to Antony Dow of Fettercairn, Kincardine. In this parish he became very popular, but his opinions failed to give satisfaction to his presbytery. In 1772 he was rejected as successor to Dow, and was even refused by the presbytery the testimonials requisite in order to obtain another living. The refusal of the presbytery was sustained by the General Assembly, and Barclay thereupon left the Scottish church and founded congregations at Sauchyburn, Edinburgh and London. His followers were sometimes called Bereans, because they regulated their conduct by a diligent study of the Scriptures (Acts xvii. 11). They hold a modified form of Calvinism.
His works, which include many hymns and paraphrases of the psalms, and a book called Without Faith, without God, were edited by J. Thomson and D. Macmillan, with a memoir (1852).