He was the son of the Rev. James Oswald (1703–1793), and nephew of the merchant Richard Oswald (1705?–1784). Initially he worked in the Glasgow firm run by his father's cousins the brothers Richard Oswald (1687–1763) of Scotstoun and Alexander Oswald (1694–1766). They left him the Scotstoun and Balshagray estates, both having died by 1766. He lived at Scotstoun House and adopted the overall name of "George Oswald of Scotstoun".
Oswald became head of the tobacco firm of Oswald, Dennistoun, & Co. of Glasgow, and partner in the Ship Bank there.[1][2] He was left the Auchincruive estate on the 1784 death of Richard Oswald his uncle, coming into possession of it on the death of his aunt in 1788.[2][3]
Alexander Oswald (01 Apr 1777–12 Jul 1821), Advocate, married Miss Anne Dalrymple (who died 22 Jun 1820), youngest daughter of Sir Hew Dalrymple Hamilton of Bargany House[6]
Elizabeth
Catherine or Katherine Cochrane, second daughter, married Robert Haldane[7]