If you do not check in online up to 2 hours before your scheduled departure time, you may check in at the airport up to 40 minutes before departure, but you will be charged an airport check-in fee.
Is it okay to check-in 4 hours before flight?
So it's a safe bet that you go to the airport at least 2 to 4 hours in advance. But keep in mind that it is just the general time. The earliest possible time to check in changes depending on your type of flight: domestic or international.
How long before a flight can you check-in Ryanair?
What happens if I check-in my flight early?
The sooner you check in, the sooner you're able to pick your seat, if you haven't already. If you're flying on a basic economy ticket, this will be the first opportunity for you to select a seat. Seat selection is first-come, first-served, so it's important to check in as soon as it's allowed.
Does Ryanair charge to check-in at airport?
If you do not check in online up to 2 hours before your scheduled departure time, you may check in at the airport up to 40 minutes before departure, but you will be charged an airport check-in fee.