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 elected as a Member of Parliament (MP) for Aldborough at a by-election in January 1784,^[1] and held the seat until the 1796 general election, which he did not contest.^[1]

He was born John Gally, but adopted the Knight name and arms in 1768 on inheriting substantial properties from his mother Elizabeth, sole heiress of the Knight family of Warsop, Firbeck and elsewhere. He inherited Firbeck Hall in Rotherham, which served as his seat. ^{[citation needed]}

He was unmarried. His estate descended via his brother to his nephew Henry Gally Knight, himself later an MP for Aldborough.

• "GALLY KNIGHT, John (?1741-1804), of Langold Park, Yorks". History of Parliament Online. Retrieved 21 March 2013.