Dún Laoghaire and Rathdown was a parliamentary constituency represented in Dáil Éireann, the lower house of the Irish parliament or Oireachtas from 1948 to 1977.
The constituency elected 3 (and later 4) deputies (Teachtaí Dála, commonly known as TDs) to the Dáil, on the system of proportional representation by means of the single transferable vote (PR-STV).
and the district electoral divisions of Ballybrack, Dundrum, Glencullen, Milltown, Rathfarnham, Rathmichael, Stillorgan and Whitechurch.
[2] transfer of Rathmichael (Bray) to the constituency of Wicklow following alteration of county boundary.
[3][4] and the townlands of Blackthorn, Brenanstown, Bullock, Carmanhall, Carmanhall and Leopardstown, Carrickmines Little, Kerrymount, Kilbogget, Loughlinstown, Rochestown, Rochestown Domain, Thomastown, in the district electoral division of Ballybrack; Mount Merrion South, in the district electoral division of Dundrum; Shanganagh, in the district electoral division of Rathmichael; in the former rural district of Rathdown No.