No, Christmas isn’t a pagan holiday, but there are elements of the holiday that can be linked to paganism.
What is paganism?
First, it’s important to demystify the “pagan.” Paganism is the term that was assigned to various groups of people by Christian missionaries within the Roman Empire during their expansion into Europe. While some populations practiced regional religions — some monotheistic, some polytheistic — others had no religious system in the context that we know it today. The main distinction is that these groups were non-Christian, and therefore bunched together under the banner of “pagan.”
Choosing the date
Now, as Christmas applies to the celebration of the birth of Jesus Christ, Christmas is decidedly not pagan. However, there are some differences of opinion when it comes to the selection of day of celebration. On the Roman calendar, December 25 was the date of the winter solstice (December 21 on the modern calendar). In a Christmas sermon, Saint Augustine of Hippo explains why Jesus Christ was born on the shortest day as such: “Hence it is that He was born on the day which is the shortest in our earthly reckoning and from which subsequent days begin to increase in length. He, therefore, who bent low and lifted us up chose the shortest day, yet the one whence light begins to increase.”
An opposing “paganization” hypothesis suggests that the Church chose December 25 to hijack the Roman holiday Dies Natalis Solis Invicti – “the birthday of the Sun” — which celebrates the Sun god Sol Invictus, adopted by Emperor Aurelian in 274 AD. There are also suggestions that Dies Natalis Solis Invicti was celebrated on December 25 in order to compete with the growing Christian faith.
As for the cultural celebration of Christmas, there are a number of callbacks to pagan traditions. While the Christmas tree first popped up in 17th-century Germany, the concept derives from the pagan practice of decorating inside homes with greenery during the winter. Santa Claus and his numerous European variations are also pulled from another pagan winter concept which details spirits traveling across the sky in the middle of the season.