Killian is a distinctive girls' name in United States, ranking #7333 in 2025 with 15 recorded births. The name reached its all-time peak in 1997 with 33 births ranking #3498. In 2025, approximately 1 in every 107,151 girls born was named Killian. RISING Recent data shows the name is currently rising.
Killian is a modern-feeling Irish-rooted name that is often connected with the same family as Cillian. It has a strong sound and a smoother international look than some more obviously Gaelic spellings.
The name became more visible through anglicised use and modern chart popularity, especially outside Ireland. It keeps a Celtic identity while feeling very accessible.