The €4million Lotto jackpot was won in the Ennis region of Co Clare.
National Lottery bosses said that the lucky punter has not yet come forward to claim their prize, as they urged players to check their tickets.
The winning numbers were 13, 18, 30, 41, 42, 44 and the bonus number was 37.
The exact store that sold Saturday's €4,041,306 winning ticket will be announced on Tuesday.
A National Lottery spokesman said: "We can reveal that this winning ticket worth more than €4 million was sold in a town in the wider Ennis region and we will announce the lucky store which sold this ticket tomorrow.
"While there will no doubt be a lot of excitement for the entire community in this town, we are urging everybody to continue to heed the advice of Government and the HSE and maintain social distancing and not to make any unnecessary visits to the store.”
It was not the only big win over the weekend, with a north Dublin player claiming a cool €250,000 jackpot in the Lotto Plus 2.
While two punters were just one number short of the top prize in the main draw, and they will take home €118,737 each.
One of the tickets was also sold in the capital, in the Spar store on Oliver Plunkett Road, Monkstown Farm, Dun Laoghaire.
While the second was purchased online by a player with an address in Co Cork.
A spokesman added: "While it is still early days we are asking everyone in Clare and Dublin to check their tickets.
"Our Cork winner will have been notified by email so for someone in the Rebel County, there is a nice email waiting for them in their inbox.
"If you are one of our winners please contact our prize claims team on 1800 666 222 or email claims@lottery.ie and we will make arrangements for you to collect your prize once COVID-19 restrictions are lifted.”
