| 1st Parliament | (1801) |
| 2nd Parliament | (1802) |
| 3rd Parliament | (1806) |
This is a list of the Irish MPs who were co-opted from the former Parliament of Ireland, to serve as members of the 1st UK Parliament from Ireland, or who were elected at subsequent by-elections. There were 100 seats representing Ireland in this Parliament.
The United Kingdom came into existence on 1 January 1801, so the terms of all the original Westminster MPs from Ireland are deemed to begin on that date. The 1st United Kingdom Parliament assembled on 22 January 1801 and was dissolved on 29 June 1802 (a length of one year, five months and seven days).