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).
In some cases, when a party label is used for the MP by Stooks Smith in a subsequent Parliament, this is noted in the Members list below.
The MPs for constituencies which retained two members after the Union (the thirty two counties and the cities of Cork and Dublin), continued in office.
In the remaining seats, which were reduced from two MPs to one, there was a drawing of lots to determine which member served at Westminster.