Home / Name Directory / Cillian
How Many People Are Named Cillian?
Estimated people named Cillian living in the U.S. today
3,462
Gender distribution
100% male · 0% female in SSA records.
Name scorecard
- Total U.S. births recorded (1880–2024): 3,492
- Peak year: 2024 (674 births)
- Estimated living today: 3,462
Cillian by age group — who carries the name today?
Cillian popularity over time (1880–2024)
Estimated living bearers by birth decade
About the name Cillian
Cillian has been recorded by the Social Security Administration since the 19th century dataset began. In total, 3,492 babies were given the name in the United States between 1880 and 2024. After adjusting each birth cohort for survival to today, an estimated 3,462 bearers are still living — roughly 1 in 98,729 Americans. The name's strongest decade shapes how old most Cillians you meet will be, which the age-group breakdown above shows directly. All figures are statistical estimates from public records; see our methodology for sources, the survival model, and the limits of the data (names given to fewer than five babies in a year are not published by the SSA).
Frequently asked questions
How many people are named Cillian in the US?
An estimated 3,462 people named Cillian are living in the United States today, based on SSA birth records from 1880 to 2024 adjusted for survival. That makes Cillian very rare — about 1 in 98,729 Americans.
Is Cillian a boy or girl name?
In SSA records, Cillian is 100% male and 0% female, so it is predominantly a male name.
When was Cillian most popular?
Cillian peaked in 2024, when 674 babies were given the name. Its current trend is rising compared with the previous decade.
How rare is the name Cillian?
Cillian ranks #4,614 of 104,819 first names recorded by the SSA, with a rarity score of 59 out of 100 (higher means rarer).