Boys' name · peaked in 2017
Killian name popularity since 1925
16,824 babies born in the US from 1925 to 2025 were named Killian (3.7% girls, 96.3% boys). Half of them were born in 2017 or earlier, so the typical Killian is about 9 years old in 2026. Killian peaked in 2017 as the #248 name for boys, and it ranked #418 in 2025.
Key facts
- US babies since 1925
- 16,824
- Named Killian, 1925–2025
- In 2025
- #418
- for boys in 2025 (770 babies)
- Girls / boys
- 96.3% boys
- 615 girls · 16,209 boys
- Most popular in
- Arizona
- 2.31× its national share
Peak year is the year Killian made up the largest share of US boys, in records going back to 1880. Typical age is based on births from 1925 on, not on who is living today.
Killian births per year, 1925–2025
2017 was the biggest year for Killian both by count and as a share of all babies.
- Fastest rise: Between 2012 and 2017, Killian became 5.7× more common, from 1 in 7,030 baby boys to 1 in 1,230.
- Steepest fall: Between 2017 and 2022, its share of baby boys fell by 36%, from 1 in 1,230 to 1 in 1,930.
Shaded on the chart. Both compare Killian's share of all US boys five years apart, counting only years with at least 100 babies named Killian.
Decade by decade
Babies named Killian in each decade, and its rank among boys' names in the middle year of the decade (1935, 1945 … 2025).
| Decade | Girls | Boys | Rank |
|---|---|---|---|
| 1925–29 | 0 | 0 | – |
| 1930s | 0 | 0 | Under 5 |
| 1940s | 0 | 0 | Under 5 |
| 1950s | 0 | 0 | Under 5 |
| 1960s | 0 | 0 | Under 5 |
| 1970s | 0 | 0 | Under 5 |
| 1980s | 28 | 132 | #4,527 |
| 1990s | 168 | 1,090 | #957 |
| 2000s | 147 | 1,824 | #1,036 |
| 2010s | 179 | 7,883 | #350 |
| 2020–25 | 93 | 5,280 | #418 |
Ranks count every name given to at least 5 boys that year, so they can go past 1,000. "Under 5" means fewer than 5 boys got the name.
Generation fingerprint
74.5% of babies named Killian from 1925 to 2025 were born in the Gen Alpha years (2013–2025). The full split by generation:
Where Killian is most popular
The index compares Killian's share of babies in each state with its share nationwide, 1925–2025 (1.50× = 50% more common). States with at least 300 babies named Killian.
| State | Index | Babies |
|---|---|---|
| Arizona | 2.31× | 436 |
| Colorado | 2.10× | 377 |
| Washington | 2.07× | 504 |
| Florida | 1.82× | 956 |
| Virginia | 1.29× | 422 |
Other spellings
Spellings that sound like Killian and were given to at least 1,000 boys from 1925 to 2025, with the year each one was most popular.
| Spelling | Boys | Peak year |
|---|---|---|
| Killian (this page) | 16,209 | 2017 |
| Cillian | 4,084 | 2024 |
| Kilian | 2,690 | 2023 |
Names with a similar story
Of the other 1999 names on this site, these six had the share of babies closest in shape to Killian's from 1925 to 2025, however common each one got. Each line is scaled to its own high; the dashed line is Killian.
Names from the same era
Other common names that peaked within two years of Killian (2017).
Source: U.S. Social Security Administration national and state baby-name data, which covers names given to at least 5 babies of one sex in a year. About the data