Augustus FitzGerald, 3rd Duke of Leinster

His Grace The Duke of Leinster PC PC (Ire)
The Duke of Leinster in Masonic regalia
Lord Lieutenant of Kildare
In office 7 October 1831 – 10 October 1874
Preceded by	New Office
Succeeded by	The Marquess of Drogheda
Personal details
Born	(1791-08-21)21 August 1791
Died	10 October 1874(1874-10-10) (aged 83)
Spouse	Lady Charlotte Augusta Stanhope
Children	Charles FitzGerald, 4th Duke of Leinster Lord Gerald FitzGerald Lady Jane Seymour FitzGerald Lord Otho FitzGerald
Parents	William FitzGerald, 2nd Duke of Leinster Emilia Olivia St George

Augustus Frederick FitzGerald, 3rd Duke of Leinster, etc. PC PC (Ire) (21 August 1791 – 10 February/October 1874) was an Anglo-Irish peer and freemason, styled Marquess of Kildare from birth until 1804. He was born and died in Carton House. FitzGerald was Grand Master of the Grand Lodge of Ireland for most of the 19th century, holding the post for 61 years from 1813 until 1874.