How Many People Are Named Cillian?
Complete statistics for the name Cillian in the United States — including rarity score, gender breakdown, age distribution, historical popularity, and state data.
Data last updated: 2025 SSA records
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Normalized logarithmic scale (0–100)
male
Population Share
How Many People Have the Name Cillian in the US?
Based on Social Security Administration birth records and age-adjusted survival modeling, approximately 3,492 people in the United States currently share the name Cillian. That works out to roughly 1 in every 94,502 Americans, placing it in the Very Rare category among all names tracked in US records. For context on where this falls on the full spectrum, see the name rarity guide.
Is Cillian a Common or Rare Name?
Cillian is classified as Very Rare when scored against the entire US population. Our rarity scale runs from Very Common (top names shared by millions) through Common, Uncommon, Rare, and Very Rare. Understanding where a name sits helps parents gauge uniqueness when choosing a baby name, genealogists narrow down records, and curious individuals settle debates about their own identity.
What Does the Name Cillian Mean?
The meaning, language of origin, cultural and religious background for Cillian are covered in full on the Cillian name meaning & origin page. For a broader look at thousands of names, browse the name meaning directory.
Gender Breakdown: Is Cillian Male or Female?
Of all recorded bearers of Cillian in SSA data, approximately 100% are male and 0% are female. Cillian is used almost exclusively as a male name in the United States. See our guide to gender-neutral names for more on how naming norms evolve.
When Was Cillian Most Popular?
The name Cillian reached peak popularity in 2024, with 668 babies registered that year. Our article on 2025 baby name trends explores these forces in detail.
Where Is Cillian Most Common in the US?
The state-by-state breakdown above shows estimated bearer counts for Cillian across all 50 states. Highly populous states like California, Texas, and New York naturally show higher counts for almost every name simply due to population size.
How Is This Data Calculated?
All figures on this page are statistical estimates, not exact government headcounts. The underlying data comes from the SSA National Baby Names dataset. Full methodology is explained on the methodology page.
How many people are named Cillian?
Approximately 3,492 people in the United States share the name Cillian, based on SSA birth records and age-adjusted survival modeling.
Is Cillian a rare name?
Cillian is classified as Very Rare in the United States. Approximately 1 in every 94,502 Americans has this name.
What does the name Cillian mean?
The meaning and origin of Cillian is displayed in the Name Meaning and Origin section at the top of this page. Browse the name meaning directory at https://howmanyofme.site/name-meaning/ for more names.
Is Cillian more male or female?
Based on SSA records, 100% of people named Cillian are male and 0% are female. The predicted gender is Male.
When was Cillian most popular?
The name Cillian reached its peak in 2024, with 668 registrations that year.
Are these statistics exact?
No. All figures are statistical estimates based on SSA birth records and age-adjusted modeling. Exact real-time name counts are not publicly available. See the methodology page at https://howmanyofme.site/methodology/ for full details.