The aviation regulator has turned down Dublin Airport Authority's request for a 50% increase in passenger charges.
The rise would have been used to fund the airport's €1.2 billion expansion plan to tackle overcrowding, which includes a €200 million terminal.
But the regulator said it would only grant a 23% rise on passenger fees.
The new charge will apply from January for the next four years.
Dublin Airport handles 18 million passengers a year, but that is expected to increase to 30 million.
Ryanair has criticised the regulator's decision, calling the increases 'unnecessary and unjustified', while employers' group IBEC said the ruling was likely to add to the confusion and uncertainty regarding the development needs of the airport.
