Cllr. Marie Therese Gallagher has announced she will not seek re-election.
The Glenties councillor said in a statement that it has been an honour to serve the people of the county since 2007.
She says it is the right time for someone else to come forward and represent the interests of workers and families in Donegal.
She succeeded Donegal Deputy Pearse Doherty.
He says she will be greatly missed.
Cllr Gallagher says she’s been considering this for some time:
Cathoirleath of Glenties Municipal, Cllr Michael McClafferty says saddened that Cllr Gallagher will not contest the next election: