Donegal East was a parliamentary constituency represented in Dáil Éireann, the lower house of the Irish parliament or Oireachtas from 1937 to 1961.
The constituency elected 4 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 administrative county of Donegal except the portion thereof which was comprised in the county constituency of Donegal West.
Following the death of Fianna Fáil TD Neal Blaney, a by-election was held on 7 December 1948.
The seat was won by the Fianna Fáil candidate Neil Blaney, son of the deceased TD.