The country is to elect its new President on Thursday 27 October.
The decision was made at the final Cabinet meeting before the summer recess.
Environment Minister Phil Hogan also announced that three referenda will also be held on the day.
These would be the poll on judicial pay, reform of the law to give more powers to Oireachtas enquiries, and one other yet to be decided.
In another development, the two local authorities in Tipperary are to be amalgamated.
Minister Hogan said the move would bring about a stronger and more cohesive local government.
Recently, the city and county councils of Limerick were also merged.