Notional results for a UK general election on 5 May 2005 Northern Ireland - Elections won by Democratic Unionist Party
| Constituency | Electorate | Turnout | Votes | Vote share | Majority |
| Belfast East | 52,899 | 58.3% | 15,152 | 49.1% | 5,877 |
| Belfast North | 52,535 | 58.1% | 13,935 | 45.6% | 5,188 |
| East Antrim | 57,966 | 54.8% | 15,766 | 49.6% | 7,304 |
| East Londonderry | 58,461 | 60.7% | 15,225 | 42.9% | 7,727 |
| Lagan Valley | 70,238 | 60.6% | 23,289 | 54.7% | 14,117 |
| North Antrim | 73,938 | 62.1% | 25,156 | 54.8% | 17,965 |
| South Antrim | 66,580 | 57.0% | 14,507 | 38.2% | 3,448 |
| Strangford | 68,570 | 54.0% | 20,921 | 56.5% | 13,049 |
| Upper Bann | 71,645 | 62.0% | 16,679 | 37.5% | 5,298 |
Turnout as calculated by the House of Commons Library, is the total number of votes cast and not spoiled, divided by the size of the electorate.
Estimates of the 2005 general election result in new constituencies
Professors Colin Rallings and Michael Thrasher, at The Elections Centre of the University of Exeter, produced estimates of the 2005 general election result as if the new constituencies recommended by the separate Parliamentary Boundary Commissions for England, Wales and Northern Ireland had then been in existence.