Part of a wingtip on one of the planes was broken off in the incident.
Emergency services are at Dublin Airport after the wingtips of two Ryanair planes, one bound for Edinburgh and the other for Brussels, hit each other on a taxi-way.
Irish state broadcaster RTÉ has reported that the incident happened as one aircraft was taxiing to a stand.
No passengers were injured, and there was no disruption to any flights.
It is understood tenders from Dublin Fire Brigade were sent to the airport as a precautionary measure.
Glenn Jordan from Bangor, County Down, was one of the passengers caught up in the disruption.
Writing on Twitter, he said the collision had been "nothing too dramatic".
"Loud bang and the plane shook for a few seconds. Kept on board for over an hour though," he said in reply to a tweet.
In a post three hours later, he said: "About to board again #Ryanair hope the rear view mirror is clear and L plates are down #collision #dublinairport."
One passenger told RTÉ people on her flight remained on board for about an hour before being allowed off.
A spokesperson for the Dublin Airport Authority has said that the airport is fully operational, although there are "minor" delays to some flights.
She said the incident happened on a taxi-way area, and the main runways are not affected.
The two planes will remain in place until investigators from the Air Accident Unit arrive.'Scraped the tail'The other plane was also damaged.
The spokesperson said this section of airport will be out of bounds for aircraft for a time, and will mean departing and arriving planes will take a slightly longer route to and from runways.
In a statement, Ryanair said: "Two of our aircraft were taxiing slowly to the runway at Dublin Airport this morning. The winglet of one aircraft appears to have scraped the tail of the other.
"There was no impact on customers on board. Ryanair has contacted the IAA and is working with them to return both aircraft to stand and allow normal operations at Dublin Airport to resume