A by-election was held in the Dáil constituency of Cork North-East in Ireland on Wednesday, 7 November 1979. It followed the death of Fianna Fáil TD Seán Brosnan on 18 April 1979.
A government motion to issue the writ of election to fill the vacancy was agreed by the Dáil on 17 October 1979.
The by-election was won by Fine Gael candidate Myra Barry. It was held on the same day as the 1979 Cork City by-election.
Both by-elections were won by Fine Gael candidates. The victory of Fine Gael in both by-elections contributed to the decision of Jack Lynch to step down as leader of Fianna Fáil and Taoiseach the following month.