Merry Christmas and Happy Christmas are both greetings used during the last part of December, around Christmastime. The first word of each is only capitalized when used as a greeting. When one is speaking of a happy or merry Christmas, the adjectives are lowercase.
Merry Christmas began as a saying in the 1500s. It was recorded in a letter as a wish that God would send the recipient a “mery Christmas”. It was solidified as a capitalized greeting by Charles Dickens in his great work A Christmas Carol.
Queen Elizabeth II, for whatever reason, did not use Dickens’ phrase. Instead, she used the phrase Happy Christmas in her broadcasts to her subjects. After her use, the term gained popularity and is still the most common form in Great Britain and Ireland.
There is debate whether or not the greeting has religious meaning and whether a more generic Happy Holidays should be used instead to respect non-Christian views. Be aware of your audience when choosing the correct phrase.
Examples
Supporters held homemade signs that said “Merry Christmas” to passing drivers, many who honked as they drove on Route 139 in Marshfield on Saturday morning. [CBS Local]
It’s going be a very, very merry Christmas now. [Sunderland Echo]
May the sweet magic of Christmas, fills your heart with love and affection, that spreads to those whom you love, Happy Christmas and New year. [Latin Times]
Seven out of 10 Filipinos are expecting to have a happy Christmas this year, the latest Social Weather Stations survey showed. [Phil Star]