Background
He was the oldest son of Thomas Southwell, 1st Viscount Southwell and his wife Margaret Hamilton, daughter of Arthur Cecil Hamilton of Castle Hamilton, Killeshandra Company
He was the oldest son of Thomas Southwell, 1st Viscount Southwell and his wife Margaret Hamilton, daughter of Arthur Cecil Hamilton of Castle Hamilton, Killeshandra Company
Trinity College.
Southwell was educated at Trinity College, Dublin. In 1780, he succeeded his father as viscount. In 1767, Southwell entered the Irish House of Commons for Limerick County, the same constituency his father had represented before, and sat for it until the following year.