Kolby is an established name used for both girls and boys that peaked in 2001 and has grown less common since.
Kolby is predominantly a boy name. In 2025 it ranked #1,225 among boys (165) and #3,618 among girls (42) — overall #2,163 across all names. The charts below show girls and boys separately.
| Year | U.S. births | U.S. + territories | ♀ Rank | ♂ Rank |
|---|---|---|---|---|
| 2025 | 207 | 207 | #3,618 | #1,225 |
| 2024 | 194 | 194 | #3,930 | #1,265 |
| 2023 | 213 | 213 | #3,456 | #1,199 |
| 2022 | 186 | 186 | #4,977 | #1,238 |
| 2021 | 176 | 176 | #5,171 | #1,263 |
| 2020 | 193 | 193 | #5,403 | #1,146 |
| 2019 | 178 | 178 | #5,235 | #1,237 |
| 2018 | 208 | 208 | #5,085 | #1,088 |
| 2017 | 201 | 201 | #4,186 | #1,146 |
| 2016 | 257 | 257 | #3,963 | #950 |
| 2015 | 307 | 307 | #4,192 | #828 |
| 2014 | 350 | 350 | #3,255 | #777 |
| 2013 | 351 | 351 | #3,385 | #749 |
| 2012 | 305 | 305 | #6,748 | #791 |
| 2011 | 360 | 360 | #4,195 | #705 |
| 2010 | 376 | 376 | #4,542 | #684 |
| 2009 | 402 | 402 | #4,749 | #662 |
| 2008 | 439 | 439 | #4,135 | #618 |
| 2007 | 401 | 401 | #6,004 | #643 |
| 2006 | 357 | 357 | #7,691 | #670 |
| 2005 | 404 | 404 | #7,009 | #586 |
| 2004 | 527 | 527 | #4,553 | #493 |
| 2003 | 572 | 572 | #4,476 | #464 |
| 2002 | 720 | 720 | #3,222 | #385 |
| 2001 | 781 | 781 | #3,283 | #359 |
| 2000 | 451 | 451 | #2,691 | #542 |
| 1999 | 459 | 459 | #2,689 | #521 |
| 1998 | 399 | 399 | #3,264 | #550 |
| 1997 | 301 | — | #4,074 | #629 |
| 1996 | 284 | — | #2,993 | #675 |
| 1995 | 300 | — | #3,395 | #634 |
| 1994 | 247 | — | #3,489 | #715 |
| 1993 | 223 | — | #3,468 | #756 |
| 1992 | 248 | — | #3,175 | #706 |
| 1991 | 228 | — | #4,412 | #708 |
| 1990 | 181 | — | #3,957 | #820 |
| 1989 | 147 | — | #3,613 | #935 |
| 1988 | 127 | — | #4,572 | #922 |
| 1987 | 123 | — | #4,774 | #917 |
| 1986 | 105 | — | #3,823 | #1,019 |
| 1985 | 110 | — | #4,058 | #965 |
| 1984 | 70 | — | #3,921 | #1,338 |
| 1983 | 56 | — | #11,114 | #1,303 |
| 1982 | 50 | — | — | #1,329 |
| 1981 | 20 | — | — | #2,455 |
| 1980 | 35 | — | — | #1,678 |
| 1979 | 31 | — | #8,489 | #2,131 |
| 1978 | 27 | — | #9,093 | #2,248 |
| 1977 | 19 | — | — | #2,415 |
| 1976 | 20 | — | — | #2,295 |
| 1975 | 18 | — | — | #2,406 |
| 1974 | 20 | — | — | #2,170 |
| 1973 | 15 | — | — | #2,563 |
| 1972 | 12 | — | — | #2,918 |
| 1971 | 5 | — | — | #5,313 |
| 1968 | 5 | — | — | #4,454 |