George Johnstone (10 December 1764 – 20 November 1813) was a British politician. He sat in the House of Commons of Great Britain and then in the House of Commons of the United Kingdom from 1800 to 1813. Johnstone was born in Pensacola, Florida. He was one of four illegitimate sons of George Johnstone, then a captain in the Royal Navy, later an admiral. His mother was Martha Ford.