There are numerous synonyms for the phrase "have a merry Christmas" that you can use to spread your festive cheer. Some popular ones include "enjoy the holiday season," "have a holly jolly Christmas," "may your Christmas be filled with joy and cheer," "happy holidays," "wishing you a wonderful and joyful Christmas," "have a blessed Christmas," and "May your Christmas be merry and bright." You can use these phrases interchangeably to wish your loved ones a happy and memorable holiday season. Whatever your preferred synonym, make sure to spread the holiday spirit all around!