Killian
Killian was given to 770 boys in 2025, #418 among boys’ names; 16,834 Americans have been recorded with it since 1915 (Social Security Administration, published May 2026).
An estimated 16,600 Americans named Killian and born in the U.S. are alive in 2026 (99% of everyone recorded); the median is 9 years old and half are between 5 and 14.
Girls and boys together; gaps are years SSA did not record (fewer than 5 births).
Births of Killian by year: SSA national baby-name file, 1880-2025, published May 8, 2026. SSA’s notes on the data.
What does Killian mean?
Wiktionary, English section
Killian is “a male given name from Irish.”
An anglicized spelling of Irish Cillian.
Meaning: Wiktionary, English section, as of Sep 25, 2026 (CC BY‑SA 4.0).
How popular is Killian?
#418 among boys’ names, 2025
Killian fell from #350 in 2015 to #418 in 2025 among boys’ names; its share of boys born fell from 0.51 to 0.45 per 1,000.
1,528 babies in 2017, the peak
Killian peaked in 2017, when 1,528 babies were given it (1,506 boys, #248 among boys’ names). The 785 births of 2025 (girls and boys) are 51% of that peak.
Births by sex.
| Year | Births | Rank | Per 1,000 boys |
|---|---|---|---|
| 2025 | 770 | #418 | 0.45 |
| 2024 | 885 | #370 | 0.51 |
| 2023 | 884 | #368 | 0.52 |
| 2022 | 903 | #364 | 0.52 |
| 2021 | 939 | #347 | 0.54 |
| 2020 | 899 | #352 | 0.52 |
| 2019 | 1,089 | #311 | 0.61 |
| 2018 | 1,229 | #287 | 0.68 |
| 2017 | 1,506 | #248 | 0.81 |
| 2016 | 1,382 | #264 | 0.73 |
Every recorded year (46)
| Year | Births | Rank | Per 1,000 boys |
|---|---|---|---|
| 2015 | 976 | #350 | 0.51 |
| 2014 | 545 | #511 | 0.28 |
| 2013 | 294 | #768 | 0.16 |
| 2012 | 270 | #819 | 0.14 |
| 2011 | 299 | #758 | 0.16 |
| 2010 | 293 | #766 | 0.15 |
| 2009 | 304 | #752 | 0.15 |
| 2008 | 274 | #800 | 0.13 |
| 2007 | 255 | #837 | 0.12 |
| 2006 | 176 | #1,036 | 0.09 |
| 2005 | 162 | #1,035 | 0.08 |
| 2004 | 151 | #1,065 | 0.08 |
| 2003 | 117 | #1,241 | 0.06 |
| 2002 | 117 | #1,197 | 0.06 |
| 2001 | 129 | #1,104 | 0.07 |
| 2000 | 139 | #1,041 | 0.07 |
| 1999 | 113 | #1,158 | 0.06 |
| 1998 | 137 | #997 | 0.07 |
| 1997 | 145 | #934 | 0.08 |
| 1996 | 145 | #909 | 0.08 |
| 1995 | 135 | #954 | 0.07 |
| 1994 | 94 | #1,182 | 0.05 |
| 1993 | 94 | #1,154 | 0.05 |
| 1992 | 71 | #1,340 | 0.04 |
| 1991 | 75 | #1,296 | 0.04 |
| 1990 | 81 | #1,216 | 0.04 |
| 1989 | 54 | #1,521 | 0.03 |
| 1988 | 22 | #2,649 | 0.01 |
| 1987 | 9 | #4,762 | under 0.01 |
| 1986 | 13 | #3,552 | 0.01 |
| 1985 | 9 | #4,522 | under 0.01 |
| 1984 | 7 | #5,293 | under 0.01 |
| 1983 | 9 | #4,330 | 0.01 |
| 1982 | 9 | #4,423 | under 0.01 |
| 1920 | 5 | #4,646 | under 0.01 |
| 1915 | 5 | #4,118 | 0.01 |
Ranks and shares: boys’ names in each year’s SSA file; share of all boys SSA recorded that year.
Is Killian a boy’s or a girl’s name?
Of the 16,834 Americans recorded as Killian, 4% are girls and 96% boys. In 2025 it went to 15 girls and 770 boys.
Years with fewer than 20 babies given the name are left blank.
Girls and boys named Killian: the SSA national file counts each sex separately.
How many people are named Killian, and how old are they?
16,600 alive in 2026, estimated
That is 99% of the 16,834 Americans ever recorded as Killian. The median Killian alive today is 9 years old; half are between 5 and 14.
The 2020 Census counted 10,658 people named Killian (547 women and girls, 10,111 men and boys). SSA’s births carried forward to Census day, April 1, 2020, predict 11,570 born in the U.S. The Census count is 8% below that prediction.
Alive today, by age
Alive today, by generation
| Generation | Born | Alive |
|---|---|---|
| Millennials | 1981-1996 | 923 |
| Generation Z | 1997-2012 | 3,290 |
| Generation Alpha | 2013-2025 | 12,400 |
An estimate, not a count. SSA’s files count people born in the United States who received a Social Security number, so anyone born abroad is not in them; before 1937 most people got a number as adults, and their survival is counted from that age.
Living estimate: SSA births carried forward with the survival rates in SSA’s cohort life tables (2024 Trustees Report) for each birth year and sex. How the estimate is made. Count: Census Bureau, first names in the 2020 Census (released April 14, 2026; names reported 100 or more times, with the Bureau’s disclosure-avoidance adjustment).
Where are babies named Killian born?
The states with the most babies named Killian are Texas, California and Florida, with 22% of its births recorded by state in 2025.
| State | Births 2025 | Rank, boys | vs. national |
|---|---|---|---|
| Texas | 58 | #553 | 0.6× |
| California | 55 | #554 | 0.6× |
| Florida | 51 | #382 | 1.0× |
| New York | 47 | #376 | 0.8× |
| North Carolina | 34 | #346 | 0.9× |
| Ohio | 31 | #362 | 1.1× |
| Michigan | 29 | #321 | 1.0× |
| Pennsylvania | 26 | #407 | 1.2× |
| Illinois | 26 | #424 | 0.8× |
| Virginia | 22 | #373 | 1.0× |
Where Killian is more common than its national share predicts
Relative to its national share, Killian is most over-represented in Washington: since 1915 it was given 1.3 times as often there as its national share each year would predict.
States: SSA state file, 1910-2025, published May 8, 2026; births count girls and boys together, and the rank is among boys’ names in the state in 2025. The file leaves out any state and year with fewer than 5 babies of the name, so small states are undercounted; each ratio compares the state’s births of Killian with the births its national share predicts year by year, for states with at least 100 births of the name.
Names spelled alike
Of these 8 names spelled alike, given to 28,056 babies since 1880, Killian is the most given (60% of them). In 2025 it was given to 785 of their 2,038 babies (39%), again the most given.
Spelled alike: names in the SSA national file with the same pattern of letters and sounds and at most two letters apart, and Wiktionary’s listed forms; births since 1880 and in 2025, and each name’s peak year, from the SSA national file, published May 8, 2026. Some are separate names, not spellings of one.
Names that rose and fell in the same decades as Killian
Names whose births rose and fell across the same decades, measured on each decade’s share of births.
Similar histories: each decade’s share of births, from the SSA national file, 1880-2025, published May 8, 2026. SSA’s notes on the data.
More about Killian and names like it
- Compare Killian and CillianBirths, ranks, peak and the living estimate side by side.
- The most given names of the 2010sKillian peaked in 2017.
- California’s most given namesThe state where SSA recorded the most babies named Killian since 1910.
- Irish namesWiktionary’s origin for Killian: every such name, by how often it is given.
- The top names of 2017The year the most babies were named Killian.
- The names of Generation AlphaMost people named Killian alive today were born 2013-2025.
- Names starting with KMost given first.