The Irish grocery market grew by 3% over the 12 weeks to December 30th, according to new figures from Kantar Worldpanel.
The data shows value sales reached €995m in December - the highest monthly total ever recorded in the Irish grocery market.
It said this was driven by shoppers spending an average of €694 on groceries in December - €151 more than the typical month.
The popularity of classic Christmas staples continued to endure, with mince pie sales rising by more than 10%.
While seasonal biscuit ranges grew by 11% and shoppers spent almost €2m on Christmas puddings alone.
For the second Christmas in a row and the fourth consecutive period overall, Dunnes was Ireland's leading retailer, accounting for 23% of the grocery market.
Dunnes was also the only one of the three biggest retailers to see a rise in shopper numbers, with almost 31,000 extra households visiting its stores compared to last year.
The retailer also performed strongly in Dublin, accounting for 27.2% of grocery sales in the capital.
Tesco and Supervalu recorded market shares of 22.3% and 21.8% respectively.
Source: Kantar Worldpanel
Despite showing a share decline on last year, both posted sales growth - with Tesco's performance primarily bolstered by its private label ranges, which contributed 57% of overall growth, and its premium Tesco Finest offering, which grew by 4.8%.
Meanwhile, Kantar said SuperValu likely benefited from any last-minute top up shopping on Christmas Eve due to its store network.
Aldi and Lidl were the strongest performing retailers over the 12 week period, with growth of 8.8% and 4.6% respectively - meaning both retailers achieved their highest ever Christmas share.
Douglas Faughnan is consumer insight director at Kantar Worldpanel: "Irish shoppers showed a willingness to splash out over the festive break.
"Branded and premium private label ranges grew by 3.8% and 11.2% respectively as shoppers spoiled themselves and their families over Christmas.
"The market also benefited from continued inflation, with prices up 1.6% compared with last year."
"The fact that Christmas fell on a Tuesday meant shoppers could take advantage of a full weekend of trading before the big day, and Saturday 22 December proved the most popular day for Christmas grocery shopping.
"The Irish public spent an additional €25m compared with the previous Saturday, making it the biggest trading day of the year with €75m going through tills."
