William Elliot (12 March 1766 – 26 October 1818) was an Irish politician who sat in the Irish House of Commons before its abolition. After the Act of Union he sat as a Whig in the House of Commons of the United Kingdom of Great Britain and Ireland.
Elliot was elected to the Irish House of Commons in 1796 as a Member of Parliament St Canice. At the 1798 election he was returned for both Carlow Borough and for St Canice, but chose to continue to sit for St Canice. He held that seat until the Parliament of Ireland was abolished at the end of 1800 by the Act of Union, when he did not initially have a seat in the new Parliament of the United Kingdom.
However, he was elected at an unopposed by-election in March 1801 as MP for Portarlington, and held that seat until the 1802 general election, when he was returned to the House of Commons of the United Kingdom for the English borough of Peterborough. He held that seat until his death in October 1818, aged 52.
- Leigh Rayment's Historical List of MPs – Constituencies beginning with "P" (part 1)
- Stooks Smith, Henry. (1973) [1844-1850]. Craig, F. W. S. (ed.). The Parliaments of England (2nd ed.). Chichester: Parliamentary Research Services. p. 236. ISBN 0-900178-13-2.
- Leigh Rayment's historical List of Members of the Irish House of Commonscites: Johnston-Liik, Edith Mary (2002). The History of the Irish Parliament 1692-1800 (6 volumes). Ulster Historical Foundation.
- Brian M. Walker, ed. (1978). Parliamentary election results in Ireland 1801–1922. Dublin: Royal Irish Academy. p. 4. ISBN 0-901714-12-7.
- Leigh Rayment's Historical List of MPs – Constituencies beginning with "P" (part 2)
- "No. 15906". The London Gazette. 1 April 1806. p. 420.
- Hansard 1803–2005: contributions in Parliament by William Elliot
|Parliament of Ireland|
John Monck Mason
| Member of Parliament for St Canice
1796 – 1800
With: John Monck Mason
Parliament of the United Kingdom
Sir Frederick Flood, Bt
John Ormsby Vandeleur
| Member of Parliament for Carlow Borough
With: Henry Prittie
|Parliament of the United Kingdom|
Frederick Trench, 1st Baron Ashtown
| Member of Parliament for Portarlington
March 1801 – 1802
Hon. Lionel Damer
Dr. French Laurence
| Member of Parliament for Peterborough
1802 – 1818
With: Dr. French Laurence to 1809
Marquess of Tavistock 1809–1812
George Ponsonby 1812–1816
Hon. William Lamb 1816
Sir Robert Heron, Bt
Hon. William Lamb
| Chief Secretary for Ireland
Sir Arthur Wellesley