An election to all 29 seats on Donegal County Council took place on 27 June 1991 as part of the 1991 Irish local elections. County Donegal was divided into 6 local electoral areas (LEAs) to elect councillors for a five-year term of office on the electoral system of proportional representation by means of the single transferable vote (PR-STV). This term was extended twice, first to 1998, then to 1999.