He was eldest son of Anne, eldest daughter of John Glassford of Dougalston, by Anne, daughter of Sir John Nisbet of Dean, and Henry Riddell of Little Govan.
[1] Riddell made genealogy and Scottish peerage law a special study.
[1] Riddell died unmarried at his house, 57 Melville Street, Edinburgh,[2] on 8 February 1862.
He left a number of manuscripts which, in terms of his will, were acquired by the Advocates' and Signet Libraries, Edinburgh.
[1] Riddell enjoyed genealogical research for its own sake, and his speciality earned him an allusion in The Lay of the Last Minstrel.