Here are some ways to say "Merry Christmas" in different languages:
French: Joyeux Noel
Spanish: Feliz Navidad
Italian: Buon Natale
German: Frohe Weihnachten
Russian: С Рождеством Христовым
Chinese: 圣诞快乐
Japanese: メリー・クリスマス
Korean: 크리스마스 축하해
Portuguese: Feliz Natal
Greek: Καλά Χριστούγεννα
Arabic: مERRY م Rcу Christ