 Gilchrist was born on 19 June 1759 in Edinburgh, and baptised on 22 June 1759 with the names John Hay Gilchrist.His father was Walter Gilchrist, but very little is known about him except that he was a merchant who disappeared the year that John was born.His mother was Henrietta Farquharson (1730-1830), originally from Dundee, who lived to the very advanced age of 100.