George Richard John MacDonnell (15 August 1780 – 6 May 1870), commonly known as Red George, was an officer in the British Army, who played a conspicuous part in the War of 1812.
He was born at Saint John's, Newfoundland, the son of the Commandant of Fort Townshend. Returned with his family to England, he was commissioned an Ensign in the 55th Foot in 1796, becoming a Captain in the 8th (The King's) Regiment of Foot in 1805. Three years later, the 8th were posted to Nova Scotia, and subsequently to [[Quebec City|Quebec.
In addition to his regimental duties, MacDonnell undertook several staff duties which made him familiar with many parts of Canada and its inhabitants. Shortly before the war with the United States broke out, the settlers of the Glengarry district, many of them discharged soldiers, petitioned the Governor General, Sir George Prevost, to be re-embodied as a unit. Prevost appointed MacDonnell as Major in the unit, the Glengarry Light Infantry.
He was promoted Lieutenant Colonel on 8 February 1813, and appointed to command the garrison at Prescott on the Saint Lawrence River.