Yes, you can—and technically must—check-in well before your flight with Ryanair, but the timing depends on your ticket type. If you have purchased a specific seat, you can check-in online or via the app up to 60 days in advance. However, if you have opted for the free "random seat allocation," the check-in window only opens 24 hours before your scheduled departure. This means for a morning flight, you would indeed check-in the night before. It is vital to complete this process digitally, as Ryanair charges a significant "Airport Check-in Fee" (often £/€55) if you arrive at the counter without having checked-in online. Once you have checked-in, you will receive a digital boarding pass on your phone. If you have a bag to drop, the "Bag Drop" desks at the airport typically open 2 hours before the flight, but the actual check-in process—securing your seat and boarding pass—should always be handled through the app at least 2 hours before takeoff.