Represented Clonmel in the Irish Parliament (1798); steadfast opponent of the Act of Union. Removed to England (c. 1800), where he devoted himself to the project of educating the English on Irish affairs.
Author of A Series of Suggestions and Observations Relative to the State of Ireland (Gloucester, 1825) and several other books on Irish politics and society.
Son of Thomas and Elizabeth (Dawson) Newenham of Coolmore, Ireland; nephew of Sir Edward Newenham. Married Mary Hoare; three children.