Donegal–Leitrim was a parliamentary constituency represented in Dáil Éireann, the lower house of the Irish parliament or Oireachtas from 1969 to 1977.
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 under the Electoral (Amendment) Act 1969, and first used at the 1969 general election to the 19th Dáil.
Following the death of Fine Gael TD Patrick O'Donnell, a by-election was held on 2 December 1970.
The seat was won by the Fianna Fáil candidate Patrick Delap.