Ko
UnisexBoys' nameGirls' nameMeaning not yet documented
Ko has been given to 85 babies in the U.S. since 1985. It was used fewer than 5 times in 2025, so it doesn't appear in the latest year's list — today it's a genuinely uncommon pick. Its peak year was 2016, with 8 recorded. It's used for both sexes: 88% boys, 12% girls all-time.
Babies named Ko, 2021
1 in 565,000
Ko over time, 1880–2025
Based on births in the U.S. Babies given the name each year. Hover the chart — or focus it and use the arrow keys — for any year. Gaps mean the name was given fewer than 5 times that year; these counts are unpublished.
Girls or boys — Ko over time
In 2021, Ko went to 0% girls and 100% boys.
A sex is only published in years it reached five applications, so a stretch at 0% or 100% means the other side stayed under that floor — not that it was never used.
How common is Ko?
Ko had fewer than 5 recorded uses in 2025, so these figures use 2021, the last year it was published.
- Among all babies, 2021
- 1 in 565,000
- 6 of 3,389,958 births
- Among boys only
- 1 in 292,000
- <0.01% of boys
- Rank, 2021
- Unranked
- Fewer than 5 uses
- Coin-flip room size
- 391,624 kids
- Even odds of a second one
Where Ko sits on the popularity scale
Chance at least one other child shares the name
If the other children were drawn at random from the 2021 national name distribution. Real classrooms cluster by region and community, so treat these as a floor, not a ceiling.
Put another way: gather 391,624 children born in 2021 and it's an even bet that one of them is another Ko. In a class of 30 the chance is Under 1%.
When Kos were born
Half of everyone ever recorded as Ko was born before 2010 — so the typical Ko is around 15 today.
- Biggest decade
- 2010s
- 37.3% of all use
- Born in the last 25 years
- 61.3%
- A modern name
- Recorded since 1950
- 75
- People you could plausibly meet
2010s — 37.3% of all recorded uses (28).
Is Ko rising or falling?
Rank movement and count movement can disagree — the number of distinct names in use keeps growing, so a name holding a steady count still slides down the list. Both are shown.
- Rank vs 1 year ago
- —
- Not ranked then
- Rank vs 5 years ago
- New entry
- Not ranked then
- Rank vs 10 years ago
- —
- Not ranked then
- Births vs 10 years ago
- —
- Not published both years
- Share of its own peak
- 0%
- Peak was 2016 (8)
- Years since peak
- 9
- Years
- Year-to-year steadiness
- Volatile
- 26.1% average annual change
Ko by the numbers
The raw record for each sex the name is used for.
As a boy's name
Names similar to Ko
Matched on shared beginnings and endings, similar length, and comparable popularity.
Sibling names for Ko
Names from the same era and popularity tier — the two things that make a sibling set feel deliberate — skipping lookalike spellings and shared initials.