Cillian
Boy name · #507 in 2025 · Distinctive
How old is the name Cillian? In official American birth records, Cillian has been tracked continuously since 1995, giving it 30 years of documented American history.
In 2025, 595 baby boys were named Cillian, placing it at #507 in the official national rankings. A decade ago it stood at #1416, so the name has been rising over the past ten years. Roughly one in every 3,025 boys born in 2025 was named Cillian.
Babies named Cillian per year. Source: Official national birth records.
The 30-year story
Cillian first appears in the Social Security records in 1995, when 5 boys received the name. Its all-time peak is essentially right now: 2024, with 668 babies and a rank of #463. Names at their peak can keep climbing — or be one trend cycle from the long slide that eventually hits most popular names. Following the curve matters more than today's snapshot: a name's position on its rise-peak-decline arc is the best predictor of how common it will feel in a kindergarten class five years from now.
Unlock the 5-year forecast and compare Cillian against up to 5 other names.
Uniqueness: will there be another Cillian in class?
On our rarity read — which blends how common Cillian is today with its five-year momentum — the name reads as "distinctive". That middle band is the sweet spot many parents hunt for: recognizable without being everywhere.
Where Cillian is most common
Geography matters for names, and Cillian is no exception. Adjusted for how many boys are born in each state, Cillian is most common in VA (0.7 per 1,000), CO (0.7 per 1,000), MA (0.7 per 1,000), NJ (0.6 per 1,000), NY (0.6 per 1,000) — against a national average of about 0.4 per 1,000 boys. These are per-capita rates, so they show where Cillian is a genuine regional favorite rather than just where the most babies are born.
Names like Cillian
Statistically, parents drawn to Cillian tend to be choosing among names with similar popularity arcs, era profiles, and sounds — the closest matches in our model are Caspian, Cassian, Lian, Kylian, and Bastian.
CaspianCassianLianKylianBastianLucianChosenKilian
Rank history (last 25 years)
| Year | Babies named Cillian | Rank |
|---|---|---|
| 2025 | 595 | #507 |
| 2024 | 668 | #463 |
| 2023 | 477 | #594 |
| 2022 | 353 | #735 |
| 2021 | 341 | #747 |
| 2020 | 228 | #957 |
| 2019 | 186 | #1078 |
| 2018 | 193 | #1052 |
| 2017 | 170 | #1126 |
| 2016 | 177 | #1105 |
| 2015 | 121 | #1416 |
| 2014 | 87 | #1730 |
| 2013 | 77 | #1851 |
| 2012 | 73 | #1942 |
| 2011 | 66 | #2035 |
| 2010 | 54 | #2354 |
| 2009 | 52 | #2451 |
| 2008 | 51 | #2467 |
| 2007 | 39 | #2974 |
| 2006 | 42 | #2744 |
| 2005 | 10 | #7096 |
| 2004 | 8 | #8143 |
| 2001 | 6 | #9243 |
| 1999 | 5 | #9912 |
| 1995 | 5 | #8868 |
Frequently asked questions
How old is the name Cillian?
In official American birth records, the name Cillian first appeared in 1995 (over 30 years ago), when 5 newborn boys received the name. It has been tracked in modern national records for 30 years.
Is Cillian a popular boy name?
Cillian ranked #507 among boys in 2025 with 595 babies given the name — outside the top 500, making it an uncommon pick. Ten years earlier it ranked #1416.
When was the name Cillian most popular?
Cillian peaked in 2024, when 668 American boys received the name (ranked #463 that year). That peak is current — the name is at or near its all-time high right now.
How rare is the name Cillian?
In 2025, roughly 1 in 3,025 newborn American boys was named Cillian. On our rarity scale (rarity blended with momentum) we classify it as "distinctive".
Data source: Official American birth records, 1880–2025, national and state files. Counts reflect registered birth records for American families.