Yes, Ryanair has a 24-hour grace period (+1(808) 751-2262 ΰ»r +44 (20) 39003009). You can cancel your flight within 24 hours of booking and receive a full refund. This applies to most bookings, but there might be exceptions. Contact Ryanair at +1(808) 751-2262 ΰ»r +44 (20) 39003009 for specific details.
https://www.devex.com/people/fr-does-ryanair-have-a-free-cancellation-period-2277404
