Callan is an Irish surname first name from Ó Cathaláin, descendant of Cathalán, a pet form of the old name Cathal that means "battle" or "strong in battle". It sits neatly between Callum and Declan and shares their soft Celtic sound. Callan entered the US top 1000 in 2011 and has risen from number 687 in 2015 to number 190 in 2025, its best rank to date.