Leitrim was a parliamentary constituency represented in Dáil Éireann, the lower house of the Oireachtas (the Irish parliament) from 1937 to 1948. The constituency elected 3 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).

The constituency was created for the 1937 general election, when the Electoral (Revision of Constituencies) Act 1935 split the old Leitrim–Sligo constituency, with County Sligo being represented from 1937 through the new Sligo constituency.^[1]

Under the Electoral (Amendment) Act 1947, the Leitrim constituency was abolished, and the Sligo–Leitrim constituency was created for the 1948 general election.^[2]

Some Dáil constituencies cross county boundaries, in order to ensure a reasonably consistent ratio of electors to TDs. The 1935 Act defines the boundaries of the Leitrim constituency as being:

"The administrative County of Leitrim and The District Electoral Divisions of: Ballintogher East, Ballynakill, Ballynashee, Cliffony North, Cliffony South, Drumcolumb, Killadoon, Kilmactranny, Rossinver East and Shancough in the administrative County of Sligo."^[1]

Note: The columns in this table are used only for presentational purposes, and no significance should be attached to the order of columns. For details of the order in which seats were won at each election, see the detailed results of that election.

• Dáil constituencies
• Politics of the Republic of Ireland
• Historic Dáil constituencies
• Elections in the Republic of Ireland