Cillian — #463 US boys' name

What the Data Says About Cillian

The Social Security Administration has registered 3,486 babies named Cillian between 1995 and 2024, spanning 30 consecutive years of U.S. birth records. As a boy's name, Cillian currently holds the #463 rank among boys for 2024. The name reached its historical peak in 2024, when 668 babies received it in a single year.

Decade-level aggregation shows that Cillian performed strongest in the 2020s, accumulating 2,064 births during that ten-year window. Across the 4 decades of recorded activity, Cillian shows a stable profile with only moderate drift from its peak decade. Geographically, the name is most concentrated in New York, which accounts for 344 births — the largest state-level total in the dataset — followed by California and Massachusetts. In total, SSA state-level files list Cillian in 37 of the 51 U.S. reporting jurisdictions.

No etymological entry is currently available for Cillian in our reference dataset. These figures derive from SSA's annual national and state-level name files, which include any name appearing at least five times in a given year or state-year; names below that threshold are suppressed for privacy and therefore excluded from the totals shown here. The 3,486 total represents a lower bound — actual usage may be higher in years or states where the count fell below the disclosure floor. This page is provided for informational and research purposes only and does not constitute personal, legal, or naming advice.