How Many People Are Named Cillian?
people named Cillian are alive in the United States today (estimate)
About 1 in 84,079 people in the US has this name
Based on 4,090 babies named Cillian in Social Security records from 1995 to 2025, and the share of each birth year still alive in 2025.
Popularity Rank
💎💎 Very Rare
Peak Year
674 births
Trend
Stable (last 10 years)
📖 Name Origin & Meaning
Meaning:
Probably from Gaelic ceall "church" combined with a diminutive suffix. This was the name of a 7th-century Irish saint who evangelized in Franconia. He was martyred in Würzburg.
Source of the meaning, origin, pronunciation and related names: Behind the Name.
⚧ Gender Distribution
Almost all of the babies given the name Cillian (99.9%) were boys.
👥 Age Distribution
The average person named Cillian alive today is about 5 years old, and 100% are under 30. Half of them were between 1 and 8 in 2025.
📈 Popularity Over Time
Cillian first appears in the records in 1995 and was given most often in 2024, to 674 babies. In 2025, 595 babies got the name.
Babies given the name each year, 1995 to 2025
🏆 Rank History
Cillian has never been one of the 100 most popular boys' names. Its best rank was #463, in 2024. In 2025 it ranked #507.
| Boys | |
|---|---|
| Rank in 2025 | #507 |
| Best rank | #463 (2024) |
| Years in the top 100 | None |
| Rank in its biggest decade | #620 in the 2020s |
📍 State-Wise Distribution
People named Cillian alive today, by the state where they were born (estimate; state records start in 1910).
More people named Cillian were born in New York than in any other state: about 392 of those alive today. Compared with the national rate in the same years, Cillian was given 3.7 times as often in Massachusetts, 2.1 times in New York and 1.9 times in Connecticut.
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