John Gally Knight (c.1741 – 20 October 1804) was an English barrister who served in the House of Commons from 1784 to 1796. He was the eldest son of Rev. Henry Gally, rector of St. Giles-in-the Fields, Holborn, Middlesex and educated at Eton College (1753–57) and Trinity Hall, Cambridge (1757), where he was awarded LLB in 1764 and elected fellow in 1764. He trained in the law at Lincoln's Inn (1756) and was called to the bar in 1765. He was unmarried. His estate descended via his brother to his nephew Henry Gally Knight, himself later an MP for Aldborough.