The ticket that won €86,732,923 in the EuroMillions draw was sold in the Dublin area.
The National Lottery also says the ticketholder has made contact with its office.
The exact location has yet to be confirmed.
The win brings the total won by EuroMillions players in Ireland to €751m since the game launched here in 2004.
Ireland is one of the luckiest places in Europe to buy a EuroMillions ticket. In the last year, there have been four EuroMillions jackpot wins here. In June 2013 a lucky player scooped €94m.
The ticket was purchased in Mace, Beaumont, Dublin 9. In September 2013 a young man from the South East shared a jackpot of over €25.6m with a player in Spain, taking home €12.8m. He purchased his lucky ticket in Ardkeen Superstores, Waterford. And in April of this year a lucky ticket purchased in Staunton’s Costcutter Express in Castlebar, Co. Mayo scooped €15m.
Since Ireland joined the EuroMillions game in 2004, players in Ireland have hit the jackpot seven times. Limerick’s Dolores McNamara continues to hold the record for the largest Irish EuroMillions win of over €115m in 2005. In July 2008, a €15m winning ticket was sold in Carrick on Suir, Co. Tipperary while a €29.4m jackpot winning ticket was sold in Dublin in June 2009.