The carrier says the majority of its Irish customers are already members
Ryanair says from next week, all customers on its Irish Ryanair.com website and mobile app will have to sign in to book a flight.
From November 1st, potential customers will have to sign up to a 'My Ryanair' account prior to completing their booking.
The carrier says the majority of its Irish customers already enjoy membership - while it says membership across Europe has doubled over the past 12 months.
"This change will make it faster and simpler for customers to book Ryanair flights and other services while at the same time increasing their online security," the airline says in a statement.
It says this process will also make it more difficult for 'screenscraper' - or third party - websites to sell Ryanair seats.
From November, Irish customers will have an account automatically generated at the payment stage on the website and app, where they will be asked to enter an e-mail address and password to complete their booking.
The carrier says this allows people to create their own personal profile, securely store payment and passport details and set their travel preferences.
It says this process will be rolled out across all markets in November and December.
Ryanair's Kenny Jacobs said: "'My Ryanair' improves the booking process for customers, gives them priority access to sales and discounts and will also help protect them from screenscraper websites, which are a rising source of complaints."
The company has confirmed to Newstalk.com that the data will be under the remit of the Irish Data Protection Commissioner.