John Maxwell-Barry, 5th Baron Farnham PC (Ire) (18 January 1767 – 20 September 1838) was an Irish Representative peer and politician. He was the son of Henry Maxwell, Lord Bishop of Meath, and grandson of John Maxwell, 1st Baron Farnham. He married on 4 July 1789 to Juliana Lucy Annesley (died 10 October 1833), daughter of Arthur Annesley, 1st Earl of Mountnorris, 8th Viscount Valentia. He died without issue and so the barony and estate passed to his brother Henry.