Ryanair’s non-priority passengers will only be able to take one piece of hand luggage into the cabin instead of two from 1 November.
Only priority-boarding customers, who pay €6 (£5) each way for the privilege, will be allowed two bags – one normal size (55cm x 40cm x 20cm) and one smaller bag (35cm x 20cm x 20cm).
Everyone else will only be able to carry the smaller size bag, such as a handbag or laptop bag.
Wheelie-style cases, that all customers could previously put in overhead lockers, will now be placed free in the hold at the boarding gate.
Ryanair said it had taken the decision because flights were being delayed because of a shortage of locker space.
Also from 1 November, the weight allowance for checked-in bags will increase from 15kg to 20kg, but the price drops from £35 to £25.
Customers with infants will still be able to take an additional changing bag (5kg) on board with them.
Passengers with waivers for medical items will also be able to board with them if they contact the airline’s special assistance line in advance.
Ryanair’s chief marketing officer, Kenny Jacobs, said he hoped the changes would “speed up the boarding of flights and eliminate flight delays”.
He said: “We believe offering bigger bags at reduced fees will encourage more customers to consider checking-in a bag, which will reduce the high volume of customers we have with two carry-on bags at the boarding gates – which is causing flight delays due to large numbers of gate bag and cabin bag offloads.”