Which ones? There’s only theee I could think of off the top of my head: O Come O Come Emannuel, We Three Kings, and What Child is This? Those are all kind of pensive and mysterious, with that modal kind of church or Renaissance sound to them.
Oh, wait, there’s also Carol of the Bells.
Otherwise, every other title of standards I’m thinking of right now is in a major key. I’m sure there’s others, but all the typical Christmas songs that come to me are in a major key.