The most popular Christmas carol is undoubtedly "Silent Night." First composed in 1818 by Franz Xaver Gruber, this classic carol has been translated into over 300 languages and dialects. It has become an essential part of the Christmas tradition for many cultures worldwide, evoking a sense of serenity and peace during the holiday season. Other popular Christmas carols include "O Holy Night," "The First Noel," "Joy to the World," and "We Wish You a Merry Christmas."