It depends. Although credit cards are not explicitly banned for gambling in Ireland, many operators prohibit their use.
Flutter Entertainment, one of the biggest companies in the industry, banned the use of credit cards at its Irish sites in April 2021, mirroring a move made by the UKGC in 2020. Flutter owns a number of high-profile betting sites and casinos including Paddy Power, Betfair, Sky Bet, and PokerStars. Fintech company Revolut has also banned use of its credit cards for gambling.
Since Ireland is in the process of developing its own regulatory gambling framework, you may not be able to use a credit card for gambling at all in the future. The issue is that it’s easier to gamble beyond your means when using a credit card — for more information on responsible gambling, visit BeGambleAware.org.