Athlone–Longford was a parliamentary constituency represented in Dáil Éireann, the lower house of the Irish parliament or Oireachtas 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 under the Electoral (Revision of Constituencies) Act 1935,^[1] replacing the old Longford–Westmeath constituency.

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

The constituency consisted of all of County Longford and parts of counties Roscommon and Westmeath. In the 1935 Act, its boundaries were defined as:^[1]

"The administrative County of Longford;

The district electoral divisions of:

Athlone West Rural, Ballydangan, Ballynamona, Caltragh, Carnagh, Carrowreagh, Castlesampson, Cloonburren, Cloonown, Crannagh, Creagh, Culliagh, Drumlosh, Dysart, Kilcar, Kiltoom, Lecarrow, Moore, Rockhill, Taghboy, Taghmaconnell, Thomastown and Turrock in the administrative County of Roscommon; and

The district electoral divisions of:

Ardnagragh, Athlone East Rural, Auburn, Carn, Castledaly, Doonis, Glassan, Killinure, Mount Temple, Moydrum, Muckanagh, Noughaval and Tubbrit and the Urban District of Athlone in the administrative County of Westmeath."

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

• Oireachtas Members Database