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

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

The constituency is in the eastern coastal area of Dún Laoghaire–Rathdown county (part of Dublin County Council till 1994), including the town of Dún Laoghaire and the villages of Ballybrack, Blackrock, Booterstown, Cabinteely (east of the N11 road), Dalkey, Deansgrange, Glasthule, Killiney, Loughlinstown, Monkstown, Sallynoggin, Shankill, and Stillorgan.

The Constituency Review Report 2023 of the Electoral Commission recommended that at the next general election, Dún Laoghaire be altered with the transfer of territory to Dublin Rathdown.

^ *: Outgoing TD Seán Barrett was Ceann Comhairle at the dissolution of the 31st Dáil and therefore deemed to be returned automatically.