Colby
#615 in the US in 2025
Colby in the United States
Between 2016 and 2025 the name has been steady.
SOURCE·US Social Security Administration, national baby-name data·Public domain. SSA lists a name only if it was given to at least 5 babies of that sex that year.·REVIEWED JUL 2026
Colby in New Zealand
In New Zealand, Colby has been registered 11 times since 2001, peaking in 2001 with 11 births. It did not clear the DIA's 10-birth reporting floor in 2025.
SOURCE·NZ Department of Internal Affairs, births by first name·CC BY 4.0. DIA lists a name only if it was given to at least 10 babies of that sex that year.·REVIEWED JUL 2026
Decade by decade in the US
| Year | Rank | Births |
|---|---|---|
| 1890 | below floor | — |
| 1900 | below floor | — |
| 1910 | below floor | — |
| 1920 | #2,336 | 13 |
| 1930 | #3,022 | 8 |
| 1940 | #3,130 | 6 |
| 1950 | #2,019 | 14 |
| 1960 | #1,400 | 32 |
| 1970 | #695 | 142 |
| 1980 | #531 | 262 |
| 1990 | #245 | 1,129 |
| 2000 | #234 | 1,465 |
| 2010 | #280 | 1,207 |
| 2020 | #618 | 439 |
Where in the United States
The states that registered Colby most often since 1888. These are lifetime totals, so they track state population as much as local taste — a name common in Wyoming will never out-count California.
| State | Births |
|---|---|
| Texas | 5,752 |
| California | 3,526 |
| Florida | 2,248 |
| North Carolina | 2,192 |
| Pennsylvania | 2,112 |
| Georgia | 1,995 |
| Louisiana | 1,902 |
| Utah | 1,790 |
| Washington | 1,682 |
| Tennessee | 1,586 |
How these figures are worked out
- Counts come straight from the registrars: the US Social Security Administration (1880–2025) and the New Zealand Department of Internal Affairs (1900–2025). Nothing is scraped from another names site.
- Ranks are computed against every name in that year's file, not just the ones this site publishes pages for — otherwise a rank would flatter every name we happen to list.
- The curve is drawn on births per 100,000 of that sex, not raw counts. Raw counts across eras are misleading: far more births were registered in 1957 than in 1890, so a flat count is a falling share.
- Each country hides small numbers — the US below 5 births a year, New Zealand below 10. A gap in a line is "below the floor", never "nobody".
SOURCE·US SSA (1880–2025) + NZ DIA (1900–2025) birth registrations·ranks and shares computed from the source files, see method·REVIEWED JUL 2026