The winning ticket for last Friday's EuroMillions jackpot worth €86.7m was sold in the Dublin area.
The National Lottery said this afternoon that the lucky winner has made contact and "is looking forward to collecting the prize".
It has not yet said which shop the winning ticket was sold in.
It is expected to be later this week before the prize can be collected because the National Lottery has to wait for funds to come in from the other lotteries around Europe.
There have been four jackpot winners in Ireland in the past 18 months, including one ticket holder who won €94m in June 2013.