One of your contributors prefers 2 ls. This is the surname derivative, one l is the correct spelling of a forename. Incidentally and more importantly the site fails to recognise that Calum is the Scottish Gaelic (Irish Gaelic is Colm) diminutive of the more widely used MALCOM or MALCOLM. Which originally meant disciple of Columba who introduced Christianity to Scotland circa 600AD.
I personally find the spelling Callum ugly and even worse the pronunciation KAY-LUM. Why would you even want to pronounce it like that? Otherwise this name is quite nice and not overly used.
― Anonymous User 5/30/2009
-4
This is a great name and very strong, but I prefer the spelling Callum. When there's only one L I want to say KAY-lum.