More than 620,000 passengers are expected to travel through Dublin Airport and 70,000 through Cork Airport over the course of the Christmas and New Year holiday period, from today until January.
It represents a 10% increase over the same period last year.
To facilitate the extra volume, the Dublin Airport Authority has advised passengers to check which terminal their flight departs from before coming to the airport.
Aer Lingus, Etihad Airways and all American carriers operate from Terminal 2 while all other airlines operate from Terminal 1.
The DAA has also asked passengers to allow themselves extra time to get to the airport and not to gift wrap presents in advance.
Elsewhere, Bus Éireann is expecting around 200,000 passenger journeys to be made before the new year.
Iarnród Éireann is expecting around 400,000 journeys to be made on intercity services over the Christmas and New Year period.
It is predicting that the busiest day for rail travel will be Friday 23 December.
Minister appoints new chairman designate of DAA
Separately, the Minister for Transport, Tourism & Sport Leo Varadkar has appointed Pádraig Ó Ríordáin as chairman designate of Dublin Airport Authority.
Mr Ó Ríordáin is a partner in law firm Arthur Cox, and was formerly managing partner of the firm.
He is also a non-executive director of Paddy Power and TVC Holdings.
Mr Ó Ríordáin is a member of the European Commission's Insolvency Law Expert Group, the advisory body to the European Commission on the development of an EU cross-border crisis management regime and resolution for the banking sector.
He replaces David Dilger, who resigned as chairman of the DAA earlier this year.
Last month it was announced that the DAA chief executive, Declan Collier, was to leave his role to take over as chief executive officer of London City Airport.
