Holly and Jack were the most popular names for babies born last December, according to the Central Statistics Office.
The agency said there was a "clear Christmas influence when it comes to naming girls", while four of the five most popular names for boys last December had biblical references.
The most popular names chosen for baby boys born throughout December 2021 were: Jack (58); Noah (42); Michael (38); James (37); and Daniel (36).
The most popular names chosen for baby girls in December 2021 were: Holly (45); Ellie (34); Grace (33); Emily (32); while Ava and Ella were joint fifth with 29 names each.
The festive trend is clear as Holly was the fifth most popular girls name in 2021 by registration but was comfortably the top name for baby girls born in December.
There were 89 babies born on Christmas Day last year, with 51 boys and 38 girls arriving. The CSO said that it was not possible to reveal the names chosen for these Christmas Day babies.
The national statistics body said that when compared with ten years ago there was a notable difference in the number of babies born on Christmas Day. In 2011 there were 70 boys and 60 girls born on Christmas Day.
Both Jack and Holly were the most popular baby names in December 2011, but there were some other changes with Sean and Adam featuring among the top five boys names and Sophie and Lucy in the most popular girl's names.
Gerard Doolan, Statistician in the Vital Statistics Division, said: "Looking at the most popular names for babies born in December compared with those whose birth was registered in December we can see a clear Christmas influence when it comes to naming girls."
"In terms of the whole of 2021, the most popular name for girls was Fiadh, while Jack topped the chart for boys' names not only in December, but for the whole of 2021," he added
