There are plenty of places still available for the Pontiff's Phoenix Park appearance
All 45,000 tickets to see the pope at Knock Shrine have been snapped up this morning.
The tickets were made available free-of-charge at 5am - and were booked out within four hours.
Anyone who missed out can still catch the pontiff in the Phoenix Park later in the day - with 500,000 places available on worldmeeting2018.ie.
World Meeting of Families spokesperson Brenda Drumm says demand for both events has been "enormous."
“We were booked out by about 10am for Knock.
“We had kind of predicted that that would happen; the capacity and the ticket issue was 45,000 was much less than what we have available for Phoenix Park.
“So we are very sorry for those who are disappointed but I think it is wonderful news and very encouraging for Knock shrine to know that there a so many people interested in going along to see Pope Francis in Knock for the World Meeting of Families.
So he will do a prayer for families while he is there so I am sure that is an image that will transfer right around the world.
“But we are certainly very encouraged by the response so far.”
Organisers estimate that applications for tickets were flying in at around 10,000 an hour this morning, with thousands in the online queue.
The international event will see worshippers from all over the world joining Pope Francis in Ireland.
Almost 10,000 international visitors have registered for tickets to the World Meeting of Families (WMOF) event at the RDS.
The main event at Croke Park is also sold out.
Ms Drumm said organisers are asking people to “bear with us.”
“Demand is enormous this morning; it is really, really strong,” she said.
“There is a queuing system on the website and I think people are a little bit alarmed when they see they are number four or five or 6,000 in the queue.
“There are 500,000 tickets; while demand is strong, we hope that anybody who wants a ticket will be able to get one.”
She said there are mixed reports regarding how long the ticket application process is taking on the website.
“This is an unprecedented ticket issue of 500,000 tickets,” she said.
“People have known that this date was coming; we have been publicising this; a lot of people have been waiting to book their tickets.
“We are also getting a lot of interest from overseas; it is an unprecedented ticket issue and we would just ask people who want to be there with us in the Phoenix to bear with us and hang in there in the queues.
“We have expanded the capacity on the server to make it more efficient for people – but you are talking about 500,000 people; there are a lot of people who want to see Pope Francis and to be with us for the mass in the Phoenix Park.”
Both events take place on august 22nd.