Kellin is a variant of Kellen and Kellan, names drawn from the Irish surname Ó Caoláin, which means "slender" or "descendant of Caolán". The spelling was made familiar by Kellin Quinn, lead singer of the rock band Sleeping with Sirens. In the United States Kellin peaked at number 1479 in 2014, at the height of the band's popularity, and ranks at number 2861 in 2025.