Ryanair will restrict passengers to just one piece of hand luggage from January - unless you have paid £5 for priority boarding.
The airline said that its two carry-on bag rule has been exploited by passengers leading to overhead cabin space getting too crowded.
They said that this is leading to problem such as boarding and flight delays due to cabin bag removals, reports The Sun.
According to the Independent, since the airline relaxed its cabin baggage policy in 2014, allowing passengers to bring two bags, the "load factor" has increased from 82 to 97 per cent - meaning there are around 25 more cabin bags to be fitted in.
This luggage squeeze is delaying flights, and affecting the swift turn-arounds of flights.
According to the BBC, Ryanair said it had been a "victim" of its own "niceness" after allowing customers to take a second carry-on bag for free.
The policy, it said, had been abused with people taking on bags up to three times the permissible size - leading to delays.
So, from 15 January, only passengers who have paid £5 for priority boarding will be allowed two bags - one normal size (55cm x 40cm x 20cm) and one smaller bag (35cm x 20cm x 20cm), reports The Sun.
Passenger wheelie bags must be placed in the hold, free of charge at the boarding gate.
Ryanair will also be increasing its check-in bag allowance from 15kg to 20kg and actually reducing its check-in bag from £35 to £25 for a 20kg bag.
Ryanair's Kenny Jacobs says the new policy should reduce delays, adding that the move was not a money-making exercise. He said: "These bag policy changes will cost Ryanair over 50m euros (£46m) per annum in reduced checked bag fees.
"However, 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."