Offaly is a parliamentary constituency represented in Dáil Éireann, the lower house of the Irish parliament or Oireachtas.

The constituency elects three deputies (Teachtaí Dála, commonly known as TDs) on the system of proportional representation by means of the single transferable vote (PR-STV).

[1] The report proposed changes to the constituencies of Ireland so as to reduce the total number of TDs from 166 to 158.

They were replaced by a re-created Laois–Offaly constituency, with the transfer of the electoral division of Portarlington North to Kildare South.

[5] For the 2024 general election, the Electoral (Amendment) Act 2023 defines the constituency as:[6] Note: The columns in this table are used only for presentational purposes, and no significance should be attached to the order of columns.