The name Kelso is a boy's name of Scottish origin. Kelso and is often added to lists like Scottish Names for Boys and discussed in our forums with posts like "Makeover name game: from one gender to the other".
From the experts:
This name of a town in Scotland, one of the earliest recorded surnames in the whole British Isles, has more vitality, and is more boyish, than the feminized Kelsey.
Some will surely associate it with the character of Michael Kelso, usually referred to simply as Kelso by his friends, portrayed by Ashton Kutcher on That '70s Show.