Kian has two roots: in Ireland it is a spelling of Cian, meaning "ancient" or "enduring", the name of Brian Boru's son-in-law, and in Persian it means "king" or "royal", after the legendary Kayanian dynasty. The name works equally well for Irish American and Iranian American families. Kian has been in the US top 1000 all century and climbed from number 945 in 2000 to number 401 in 2025, its best rank yet.