George Nugent, 1st Marquess of Westmeath

George Thomas John Nugent, 1st Marquess of Westmeath (17 July 1785 – 5 May 1871), styled Lord Delvin between 1792 and 1814 and known as the Earl of Westmeath between 1814 and 1821, was an Anglo-Irish peer.

Background Nugent was born in Clonyn, County Westmeath, the only surviving son of George Frederick Nugent, 7th Earl of Westmeath, and Maryanne, daughter of Major James St John Jeffereyes and Arabella Fitzgibbon. His parents divorced in 1796 after his father's discovery of his mother's affair with Augustus Cavendish-Bradshaw, which also resulted in a celebrated action for criminal conversation. Both his parents were quickly remarried, his mother to her lover, and his father to Lady Elizabeth Moore, daughter of Charles Moore, 1st Marquess of Drogheda.

Career Delvin was an officer in the Coldstream Guards and served in the Egyptian Campaign. He succeeded his father in the earldom in December 1814. As these were Irish peerages they did not entitle him to an automatic seat in the House of Lords. However, in 1831 he was elected an Irish representative peer. The same year he was also appointed Lord-Lieutenant of Westmeath, a post he held until his death. he is an ancestor of Annemarie, Duchess of Parma.

Lord Westmeath died in May 1871, aged 85, when the marquessate became extinct. His two half-brothers, Robert and Thomas, had predeceased him, without issue. He was succeeded in his remaining titles by his kinsman, Anthony Nugent, of the junior branch of the family which had the title Baron Nugent of Riverston. The Marchioness of Westmeath died in September 1882.