Colby Boy
How popular is Colby?
#615 boy name in 2025
455 baby boys were named Colby in the US in 2025, making it the 615th most popular boy name. Another 60 girls got the name (#2,822 for girls).
Colby popularity over time
Boys Girls
| Rank in 2025 | #615 for boys (▼ 32 from 2024) |
|---|---|
| Babies in 2025 | 455 boys, 60 girls |
| 10-year trend | Falling (-32% babies vs 2015) |
| Earlier ranks | #456 in 2015, #618 in 2020 |
| Peak year | 2001 (3,859 boys) |
| Highest rank | #99 in 2001 |
| First recorded | 1888 |
| Boys vs girls (last 10 years) | 90% boys, 10% girls |
| Chance a classmate shares it | 0.4% in a class of 25 kids born in 2025 |
Colby counting every spelling
Social Security counts each spelling as its own name. Adding together the spellings that sound alike, the Colby family of names ranked #472 for boys in 2025 (#465 the year before), with 626 babies in all.
| Spelling | Boys in 2025 | Share |
|---|---|---|
| Colby | 455 | 73% |
| Kolby | 165 | 26% |
| Kolbey | 6 | 1% |
Spellings are grouped by how they sound, using our own rules, so a few groupings may not match how your family says the name.
Where Colby is most popular
Babies named Colby per 1,000 boys born in each state, 2021 to 2025. Darker means more common.
- New Hampshire: 2.2 per 1,000 (49 boys)
- Maine: 1.4 per 1,000 (28 boys)
- Massachusetts: 0.7 per 1,000 (92 boys)
- Connecticut: 0.6 per 1,000 (43 boys)
- West Virginia: 0.6 per 1,000 (20 boys)
Colby by decade
| Decade | Baby boys | Best rank |
|---|---|---|
| 1880s | 5 | #1,030 |
| 1910s | 32 | #2,731 |
| 1920s | 90 | #2,335 |
| 1930s | 73 | #2,326 |
| 1940s | 137 | #1,459 |
| 1950s | 225 | #1,410 |
| 1960s | 430 | #841 |
| 1970s | 2,754 | #413 |
| 1980s | 6,843 | #250 |
| 1990s | 14,261 | #197 |
| 2000s | 19,182 | #99 |
| 2010s | 7,199 | #280 |
| 2020s | 2,740 | #583 |
Boy names about as popular as Colby
Questions
- Is Colby a boy or girl name?
- Colby is mostly a boy name. Over the last 10 years, 90% of babies named Colby were boys.
- How popular is the name Colby?
- 455 baby boys were named Colby in the US in 2025, making it the 615th most popular boy name. Another 60 girls got the name (#2,822 for girls).
- When was Colby most popular?
- Colby peaked in 2001, when 3,859 boys were given the name. Its highest rank was #99 in 2001.
- How many people are named Colby?
- 58,155 babies have been named Colby in the US since 1880. We estimate about 56,286 of them are alive in 2026, with a median age of 25.
- Where is Colby most popular?
- From 2021 to 2025, Colby was most common in New Hampshire, at 2.2 of every 1,000 boys born there.
Source: Social Security Administration baby name data, 1880 to 2025 (names given to at least 5 babies of a sex in a year). Living-people and median-age figures are our estimates using US life tables. How we calculate.