Cillian is a distinctive boys' name in United States, ranking #507 in 2025 with 595 recorded births. The name reached its all-time peak in 2024 with 668 births ranking #463. In 2025, approximately 1 in every 2,871 boys born was named Cillian. RISING Recent data shows the name is currently rising.
Cillian is a well-loved Irish name with a soft, distinctive sound. It is often explained through church-related Gaelic roots, though exact older interpretations vary a little.
The name is familiar in Ireland through saints and tradition and has become far more visible internationally in recent years. Modern recognition has also grown through public figures such as Cillian Murphy.