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).

A third constituency with this name was created in the north-western area of the city by the Electoral (Amendment) Act 1980 and first used at the 1981 general election.

The Electoral (Amendment) Act 2023 defines the constituency as:[5] New Kilmainham and Usher's Quay part of Dublin South.

Drumcondra Rural Number One (except the part thereof which is comprised in the constituency of Dublin North) and Drumcondra Rural Number Two (except the parts thereof which are comprised in the constituencies of Dublin North and Dublin North-Central); and the townlands of Charlestown, Jamestown Great, Jamestown Little, Meakstown, Poppintree, in the district electoral division of Finglas, and that part of the townland of Kildonan in the district electoral division of Finglas, situated east of an imaginary line joining— (a) the point of intersection of the boundary of the county borough of Dublin by the western boundary of No.

Following the resignation of Fianna Fáil TD Seán T. O'Kelly on his election as President of Ireland, a by-election was held on 4 December 1945.

Love, Murray, Ó Cuinneagáin, Staines, Sheppard, Keogh and Macken all lost their deposits.