Donegal West was a parliamentary constituency represented in Dáil Éireann, the lower house of the Irish parliament or Oireachtas from 1937 to 1961.
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).
It consisted of the district electoral divisions of: Note: The columns in this table are used only for presentational purposes, and no significance should be attached to the order of columns.
Following the death of Fianna Fáil TD Brian Brady, a by-election was held on 16 November 1949.
The seat was won by the Fine Gael candidate Patrick O'Donnell.