Sir William Payne-Gallwey, 2nd Baronet (1807 – 19 December 1881) was an English Conservative Party politician who sat in the House of Commons from 1851 to 1880.
Payne-Gallwey was the son of Sir William Payne-Gallwey, 1st Baronet and his wife Harriet Quin, daughter of the 1st Earl of Dunraven. His father was a British Army general and governor of the Leeward Islands. Payne-Gallwey was a major in the 7th Fusiliers and succeeded his father in the baronetcy in 1831. He was a deputy lieutenant and J.P. for the North Riding of Yorkshire.
At a by-election in March 1851, Payne-Gallwey was elected unopposed as the Member of Parliament (MP) for Thirsk. He was re-elected without a contest in the next four general elections, and in contested elections in 1868 and 1874. He held the seat until he stood down at the 1880 general election.
Payne-Gallwey died at the age of 74, as a result of severe internal injuries sustained after falling upon a turnip while out shooting in the parish of Bagby.
Payne-Gallwey married Emily Anne Russell, daughter of Sir Robert Frankland Russell, 7th Baronet in 1847. They had four sons and three daughters. He was succeeded by his eldest son, Ralph.