Kolby
Girl name · #3608 in 2025 · Very rare
How old is the name Kolby? In official American birth records, Kolby has been tracked continuously since 1978, giving it 47 years of documented American history.
Kolby is currently the #3608 girl name in the United States — 42 babies received it in 2025. A decade ago it stood at #4144, so the name has been rising over the past ten years. Roughly one in every 42,857 girls born in 2025 was named Kolby.
Babies named Kolby per year. Source: Official national birth records.
The 47-year story
Kolby first appears in the Social Security records in 1978, when 6 girls received the name. Its peak came in 2000, when 55 girls were named Kolby — good for #2672 that year. Today's parents encounter it on its way down the popularity curve, which for many parents is exactly the appeal. 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 Kolby against up to 5 other names.
Uniqueness: will there be another Kolby in class?
On our rarity read — which blends how common Kolby is today with its five-year momentum — the name reads as "very rare". A high score means genuine rarity — your Kolby will likely be the only one in the room, with the occasional spelling-out as the price.
Where Kolby is most common
State-level data for Kolby is too sparse in 2025 to rank by rate — in most states its count falls below the SSA's per-state reporting threshold (counts under 5 are withheld).
Names like Kolby
Statistically, parents drawn to Kolby tend to be choosing among names with similar popularity arcs, era profiles, and sounds — the closest matches in our model are Colby, Kaley, Katya, Kamry, and Karley.
ColbyKaleyKatyaKamryKarleyKailyKayleyKarson
Rank history (last 25 years)
| Year | Babies named Kolby | Rank |
|---|---|---|
| 2025 | 42 | #3577 |
| 2024 | 38 | #3892 |
| 2023 | 46 | #3428 |
| 2022 | 27 | #4907 |
| 2021 | 25 | #5091 |
| 2020 | 23 | #5314 |
| 2019 | 25 | #5163 |
| 2018 | 26 | #5007 |
| 2017 | 35 | #4147 |
| 2016 | 38 | #3923 |
| 2015 | 35 | #4144 |
| 2014 | 50 | #3226 |
| 2013 | 47 | #3367 |
| 2012 | 19 | #6576 |
| 2011 | 35 | #4151 |
| 2010 | 32 | #4494 |
| 2009 | 31 | #4677 |
| 2008 | 38 | #4089 |
| 2007 | 23 | #5895 |
| 2006 | 16 | #7482 |
| 2005 | 17 | #6820 |
| 2004 | 30 | #4492 |
| 2003 | 29 | #4418 |
| 2002 | 44 | #3196 |
| 2001 | 42 | #3256 |
Frequently asked questions
How old is the name Kolby?
In official American birth records, the name Kolby first appeared in 1978 (over 47 years ago), when 6 newborn girls received the name. It has been tracked in modern national records for 47 years.
Is Kolby a popular girl name?
Kolby ranked #3608 among girls in 2025 with 42 babies given the name — outside the top 500, making it an uncommon pick. Ten years earlier it ranked #4144.
When was the name Kolby most popular?
Kolby peaked in 2000, when 55 American girls received the name (ranked #2672 that year). Since 2000 the name has declined from that high.
How rare is the name Kolby?
In 2025, roughly 1 in 42,857 newborn American girls was named Kolby. On our rarity scale (rarity blended with momentum) we classify it as "very rare".
Data source: Official American birth records, 1880–2025, national and state files. Counts reflect registered birth records for American families.