Kolby vs Kolleen
American parents have registered 13,001 Kolbys since 1880, against 1,016 Kolleens. Kolby is still ahead, with 207 babies in 2025.
Babies given each name, 1880–2025
Kolby Kolleen
Each line is every baby given the name that year, girls and boys added together — the only count that means the same thing for both names. A line breaks where the name fell below five babies in a year — the point at which the SSA stops publishing it — rather than being drawn through a figure nobody published. A single published year in a gap shows as a dot.
Who was ahead
Of the 80 years in which either name was published, Kolby for 49 years and Kolleen for 31 years. The lead changed hands once.
Side by side
| Kolby | Kolleen | |
|---|---|---|
| Total US births | 13,001 | 1,016 |
| Most in one year | 781 | 48 |
| Babies in 2025 | 207 | under 5 |
| Estimated living today | 13,000 | 910 |
| Median age today | 21 | 55 |
| Peak year | 2001 | 1962 |
| Best rank | 359th boys | 1,627th girls |
| Rank in 2025 | 1,222nd | unranked |
| First recorded | 1968 | 1946 |
| Girls / boys | 1,351 / 11,650 | 1,016 / 0 |
A rank is a position within one sex’s list for one year, so the two rank rows are not subtracted from one another and the winning column is not marked on them. The living figure is a life-table estimate, not a count.
Which name is older
Half of the Kolleens alive today are over 55; half the Kolbys are over 21. That is 34 years between them: two names in use at the same time, worn by two different generations.
Where each one is strongest
- Kolby Utah (5.8×), Idaho (4.4×), Oklahoma (3.0×)
- Kolleen Michigan (7.0×), California (3.1×), New York (2.7×)
How much commoner the name is in that state than it is nationally, from births recorded since 1910.
Compare something else
Related comparisons
Social Security Administration birth records, 1880–2025, public domain. Full histories: Kolby and Kolleen.