After remaining with his regiment in Ireland for two years, FitzGerald was sent to Gibraltar in 1816 and to Canada in 1818. He became Commandant of Quebec in 1818 and, having been promoted to brevet colonel on 12 August 1819, he went on to be Commandant of Montreal, Quebec. He was given command of the 20th Regiment of Foot in Bombay on 5 February 1824 before being promoted to major-general on 22 July 1830 and being advanced to Knight Commander of the Order of the Bath on 13 September 1831. He was given a divisional command in the Madras Army in 1838 and but shortly afterwards transferred to Bombay where he was given a divisional command of the Bombay Army. Returning to the United Kingdom in early 1841, he was promoted to lieutenant-general on 23 November 1841 and to full general on 20 June 1854.