George Dickinson Hadley FRCP (30 June 1908 – 14 August 1984) was an English gastroenterologist. He served in the Royal Army Medical Corps during the Second World War and was taken prisoner during the Dunkirk evacuation. He made several failed escape attempts during his incarceration. In 1963 he introduced the gastrocamera to Britain, thus enabling the development of endoscopy in that country.