 He was the son of James Lundin (1707–1781) and the former Lady Rachel Bruce (d. 1769), a daughter of Thomas Bruce, 7th Earl of Kincardine.His elder sister, Veronica Drummond, married Duncan Campbell of Kames, and his elder brother, was Thomas Drummond, Lord Drummond.The Lundins descended from Thomas de Lundin, a natural son of King William the Lion.