| Election | Constituency | Member | Party | Notes |
|---|
| 1801, 1 January | County Antrim 2 members | Rt Hon. John Staples | | |
| Edmond Alexander MacNaghten | | Classified Tory in the 2nd Parliament |
| 1801, 1 January | Armagh | Patrick Duigenan | Tory | Appointed Commissioner of Compensation 1801 |
| 1801, 2 March [a] | |
| 1801, 1 January | County Armagh 2 members | Hon. Archibald Acheson | | Classified Tory in the 2nd Parliament |
| Robert Camden Cope | | |
| 1801, 1 January | Athlone | William Handcock | | |
| 1801, 1 January | Bandon | Sir Broderick Chinnery, Bt | Whig | |
| 1801, 1 January | Belfast | James Edward May | Tory | |
| 1801, 1 January | Carlow | Hon. Henry Sadleir Prittie | | The 2nd Baron Dunalley from 3 January 1801 |
| 1801, 21 March [a] | Hon. Francis Aldborough Prittie | | Resigned |
| 1801, 30 July [a] | Charles Montague Ormsby | Tory | |
| 1801, 1 January | County Carlow 2 members | William Henry Burton | | |
| Sir Richard Butler, Bt | | |
| 1801, 1 January | Carrickfergus | Noah Dalway | | |
| 1801, 1 January | Cashel | Richard Bagwell | | Resigned |
| 1801, 9 December [a] | John Bagwell (c. 1780-1806) | | |
| 1801, 1 January | County Cavan 2 members | Francis Saunderson | Whig | |
| Nathaniel Sneyd | Tory | |
| 1801, 1 January | County Clare 2 members | Hon. Francis Nathaniel Burton | | |
| Hugh Dillon Massy | | |
| 1801, 1 January | Clonmel | seat vacant | | No co-option (both Irish Parliament seats vacant) |
| 1801, 13 February [a] | Rt Hon. William Bagwell | Tory | |
| 1801, 1 January | Coleraine | Walter Jones | Tory | |
| 1801, 1 January | Cork 2 members | Hon. John Hely-Hutchinson | Whig | Created 1st Baron Hutchinson 1801 |
| Mountifort Longfield | Tory | |
| 1802, 8 January [a] | Hon. Christopher Hely-Hutchinson | Whig | |
| 1801, 1 January | County Cork 2 members | Viscount Boyle | | Classified Whig in the 3rd Parliament |
| Robert Uniacke Fitzgerald | | |
| 1801, 1 January | County Donegal 2 members | Henry Vaughan Brooke | Tory | |
| Viscount Sudley | Tory | |
| 1801, 1 January | County Down 2 members | Viscount Castlereagh | Tory | |
| Francis Savage | | |
| 1801, 1 January | Downpatrick | Clotworthy Rowley | | Appointed Commissioner of Compensation 1801 |
| 1801, 10 March [a] | Samuel Campbell Rowley | | |
| 1801, 1 January | Drogheda | Edward Hardman | | |
| 1801, 1 January | Dublin 2 members | John Claudius Beresford | Tory | |
| Rt Hon. George Ogle | Tory | |
| 1801, 1 January | County Dublin 2 members | Hans Hamilton | Tory | |
| Frederick John Falkiner | Tory | |
| 1801, 1 January | Dublin University | Hon. George Knox | Tory | |
| 1801, 1 January | Dundalk | seat vacant | | No co-option (both Irish Parliament seats vacant) |
| 1801, 28 February [a] | Rt Hon. Isaac Corry | Tory | |
| 1801, 1 January | Dungannon | Hon. John Knox | | Died |
| 1801, 21 November [a] | Sir Charles Hamilton, Bt | | Classified Tory in the 2nd Parliament |
| 1801, 1 January | Dungarvan | Edward Lee | Whig | |
| 1801, 1 January | Ennis | John Ormsby Vandeleur | Tory | |
| 1801, 1 January | Enniskillen | Hon. Arthur Cole Hamilton | Tory | |
| 1801, 1 January | County Fermanagh 2 members | Mervyn Archdall (senior) | Tory | |
| Viscount Cole | Tory | |
| 1801, 1 January | Galway Borough | St. George Daly | | Resigned |
| 1801, 10 March [a] | John Brabazon Ponsonby | Whig | |
| 1801, 1 January | County Galway 2 members | Richard Le Poer Trench | | |
| Richard Martin | | |
| 1801, 1 January | County Kerry 2 members | James Crosbie | Tory | |
| Rt Hon. Maurice Fitzgerald (The 18th Knight of Kerry) | Whig | Appointed Commissioner of the Treasury 1801 |
| 1801, 5 March [a] | |
| 1801, 1 January | County Kildare 2 members | Maurice Keatinge | | |
| John La Touche | Whig | Not John La Touche, MP elected 1802 |
| 1801, 1 January | Kilkenny | William Talbot | | Resigned |
| 1802, 2 March [a] | Richard Archdall | | |
| 1801, 1 January | County Kilkenny 2 members | Hon. James Wandesford Butler | Whig | |
| Rt Hon. William Brabazon Ponsonby | Whig | |
| 1801, 1 January | King's County 2 members | Sir Lawrence Parsons, Bt | | Classified Tory in the 2nd Parliament |
| Denis Bowes Daly | Tory | |
| 1801, 1 January | Kinsale | William Rowley | | Appointed Commissioner of Irish Revenue 1801 |
| 1801, 20 February [a] | |
| 1801, 1 January | County Leitrim 2 members | Viscount Clements | Whig | |
| Rt Hon. Theophilus Jones | Tory | |
| 1801, 1 January | Limerick | Henry Deane Grady | | |
| 1801, 1 January | County Limerick 2 members | John Waller | | |
| William Odell | | Classified Tory in the 4th Parliament |
| 1801, 1 January | Lisburn | George Hatton | Tory | |
| 1801, 1 January | Londonderry | Henry Alexander | | |
| 1801, 1 January | County Londonderry 2 members | Hon. Charles William Stewart | Tory | |
| seat vacant | | Beresford became Marquess of Waterford 1800 |
| 1801, 14 January [a] | Sir George Fitzgerald Hill, Bt | Tory | |
| 1801, 1 January | County Longford 2 members | Sir Thomas Fetherston, Bt | | Classified Tory in the 3rd Parliament |
| Sir William Gleadowe-Newcomen, Bt | | |
| 1801, 1 January | County Louth 2 members | John Foster | | Classified Tory in the 2nd Parliament |
| William Charles Fortescue | | |
| 1801, 1 January | Mallow | John Longfield | | |
| 1801, 1 January | County Mayo 2 members | Rt Hon. Denis Browne | | Classified Tory in the 2nd Parliament |
| George Jackson | | |
| 1801, 1 January | County Meath 2 members | Hamilton Gorges | | |
| Sir Marcus Somerville, Bt | | Classified Whig in the 2nd Parliament |
| 1801, 1 January | County Monaghan 2 members | Richard Dawson | | |
| Warner William Westenra | | Succeeded as 2nd Baron Rossmore on 6 August 1801 |
| 1801, 1 December [a] | Charles Powell Leslie II | Tory | |
| 1801, 1 January | New Ross | Robert Leigh | | |
| 1801, 1 January | Newry | John Moore | | |
| 1801, 1 January | Portarlington | Frederick Trench | | Created the 1st Baron Ashtown on 27 December 1800 and never sat, though elected |
| 1801, 5 March [a] | William Elliot | | |
| 1801, 1 January | Queen's County 2 members | Sir John Parnell, Bt | | Died 6 December 1801 |
| Rt Hon. Charles Henry Coote | | The 2nd Baron Castle Coote from 1 March 1802 |
| 1801, 28 December [a] | Hon. William Wellesley-Pole | | |
| 1802, 5 April [a] | Henry Brooke Parnell | | |
| 1801, 1 January | County Roscommon 2 members | Arthur French | Whig | |
| Thomas Mahon | Whig | |
| 1801, 1 January | Sligo | Owen Wynne | Tory | |
| 1801, 1 January | County Sligo 2 members | Joshua Edward Cooper | Tory | |
| Charles O'Hara | Whig | |
| 1801, 1 January | County Tipperary 2 members | Viscount Mathew | | |
| John Bagwell (c. 1752-1816) | | |
| 1801, 1 January | Tralee | Arthur Moore | | |
| 1801, 1 January | County Tyrone 2 members | Viscount Corry | | The 2nd Earl Belmore from 2 February 1802 |
| James Stewart | | |
| 1802, 1 March [a] | Rt Hon. John Stewart | | |
| 1801, 1 January | Waterford | William Congreve Alcock | Tory | |
| 1801, 1 January | County Waterford 2 members | Rt Hon. John Beresford | Tory | |
| Richard Power | Whig | |
| 1801, 1 January | County Westmeath 2 members | William Smyth | | |
| Gustavus Hume-Rochfort | | Classified Tory in the 5th Parliament |
| 1801, 1 January | Wexford | Francis Leigh | | Resigned |
| 1801, 20 February [a] | Ponsonby Tottenham | | |
| 1801, 1 January | County Wexford 2 members | Viscount Loftus | Tory | |
| Abel Ram | Tory | |
| 1801, 1 January | County Wicklow 2 members | William Hoare Hume | Whig | |
| seat vacant | | Death of Westby on 30 November 1800 |
| 1801, February | George Ponsonby | Whig | First contested UK election, in Ireland |
| 1801, 1 January | Youghal | Sir John Keane, Bt | Tory | Created baronet 1 August 1801 |