William Hamilton Maxwell (June 30, 1792 in Newry, County Down, Ireland – December 29, 1850 in Musselburgh, Scotland) was a Scots-Irish novelist.
He was educated at Trinity College, Dublin. He claimed to have entered the British Army and seen service in the Peninsular War and the Battle of Waterloo, but this is generally believed to be untrue. Afterwards he took orders, but was deprived of his living for non-residence.
His novels, O'Hara (1825), and Stories from Waterloo (1834) started the school of rollicking military fiction, which culminated in the novels of Charles Lever. Maxwell also wrote a Life of the Duke of Wellington (1839–1841), and a History of the Irish Rebellion of 1798 (1845).
Maxwell married Mary Dobbin, daughter of Leonard Dobbin, MP for Armagh.