Merry Christmas to you!
Since you did not specify which Gaelic, here are two answersNollaig Chridheil is ScottishIrish would be Nollaig faoi shéan agus faoi shonas duit!
"Nollaig Chridheil" means "Merry Christmas"
It is written Nollaig Chridheil and pronounced like 'nollick hree-ell'.
Nollaig Chridheil
In scottish Gaelic Merry Chistmas is Nollaig Chridheil
Nollaig Chridheil agus Bliadhna Mhath Ùr
The Scottish Gaelic for "Merry Christmas and happy new year"
Irish Gaelic: Nollaig shona dhuit! (or dhaoibh, pl.) Scots Gaelic: Nollaig Chridheil
Nollaig chridheil in Scots Gaelic Nollaig shona in Irish Gaelic and Nollag Ghennal in Manx
In Scottish Gaelic Merry Christmas is Nollaig chridheilPronounced "nollik chree-hel"
Since you did not specify which Gaelic, here are two answersNollaig Chridheil is ScottishIrish would be Nollaig faoi shéan agus faoi shonas duit!