Irish shoppers spent a record €995 million in supermarkets in December.
Kantar says it's the highest monthly total ever recorded in the Irish grocery market.
The group says Irish consumers spent an average of €694 each last month - €151 more than the typical month.
Saturday December 22nd was the most popular day for Christmas grocery shopping, where €75 million went through tills nationwide.
Mince pie sales grew by 10%, while biscuits also enjoyed an 11% surge in popularity.
Meanwhile, almost €2 million was spent on Christmas puddings.
Dunnes captured the highest market share over the Christmas period for the second year in a row, accounting for 23% of Irish grocery sales .