Methuen was the son of Paul Cobb Methuen of Corsham, Wiltshire, and his wife Matilda (née Gooch). He sat as Member of Parliament for Wiltshire from 1812 to 1819 and for Wiltshire North from 1833 to 1837. He was appointed High Sheriff of Wiltshire for 1831 and raised in 1838 to the peerage as Baron Methuen, of Corsham in the County of Wiltshire.^[3]

Lord Methuen married Jane Dorothea, daughter of Sir Henry Paulet St John-Mildmay, in 1810. She died in 1846. Lord Methuen survived her by three years and died in September 1849, aged 70. He was succeeded in the barony by his son Frederick. His grandson Paul Methuen, 3rd Baron Methuen, became a prominent military commander.

Methuen played in a first-class cricket match in 1816 for Marylebone Cricket Club (MCC) but was dismissed without scoring in both his innings. He was born at Marylebone, London, and died aged 69 at Westminster.^[4]

• Kidd, Charles, Williamson, David (editors). Debrett's Peerage and Baronetage (1990 edition). New York: St Martin's Press, 1990, ^{[page needed]}
• Leigh Rayment's Peerage Pages ^{[self-published source] [better source needed]}
• Leigh Rayment's Historical List of MPs
• Lundy, Darryl. "FAQ". The Peerage.^{[unreliable source]}