He was born in Wigtown on 1 May 1737 the son of David McQuhae, a local magistrate and his wife Margaret Laurie.
[1][2] He studied at the University of Glasgow and was licensed by the Presbytery of Wigtown to preach as a Church of Scotland minister on 24 March 1762.
On Reid's death in 1763 McQuhae was presented as the new minister of St Quivox by James Murray of Broughton.
In 1806 he declined the position of Moderator of the General Assembly and the post was instead given to Rev William Taylor of St Enoch's Church in Glasgow.
They had several children, most of whom died young: Richard McQuhae (1766–1805) died in Jamaica; Sarah (1769–1778); Margaret (1770–1836); David (1773–1775); Elizabeth (1774–1778); Glencairn (daughter) (1776–1802); Charles (daughter) (1778–1855) married Alexander McDowal.