If we are talking about the "True spirit of christmas" No it is not pagan and has it's roots in Christianity
If we are talking about traditions and rituals added onto that well traditions and rituals have been borrowed and shared by religions the world over.
Modern christmas is similar to the yule tide [time? not sure which honestly] of old. Which is pagan itself. As stated previously based around the winter solstice and took up several days [i could be mistaken it is very late please fact check].