Richard was the only son of Thomas Southwell and his wife Elizabeth Starkey. His father was the 1st Baronet Southwell of Castle Mattress, County Limerick. His mother was the daughter of William Starkey.
Family tree
Richard Southwell with his wife, parents, and other selected relatives.[a]
^Burke, John (1863). Bernhard Burke (ed.). Burke's Genealogical and Heraldic History of the Landed Gentry of Great Britain and Ireland. Vol. II. London: Harrison. p. 1738.
^Burke, John (1832). A Genealogical and Heraldic History of the Peerage and Baronetage of the British Empire. Vol. II (4th ed.). London: Henry Colburn and Richard Bentley. p. 465.
^Leigh Rayment's historical List of Members of the Irish House of Commons. Cites: Johnston-Liik, Edith Mary (2002). The History of the Irish Parliament 1692-1800 (6 volumes). Ulster Historical Foundation.