Is Koi a boy or girl name?

Koi is a unisex name. Of the 1,482 Americans recorded with the name since 1880, 45.1% were girls and 54.9% were boys. It changed hands in 2023, and has gone mainly to girls since.

Name Legacy

Koi

Recorded 1995–2025 · United States

Koi was most popular in 2023, when 127 American babies were given the name — ranking #3,014 that year. In 2025 it ranked #3,056, with 124 births. Across 1880–2025 the Social Security Administration has recorded 1,482 people named Koi.

Koi over time

Births per year. The dot marks Koi’s peak in 2023. Gaps are years the SSA suppressed, which it does for any name given to fewer than five babies.

Is Koi a boy’s or a girl’s name?

Across the whole record Koi is a unisex name — 45.1% of the 1,482 Americans given it were girls and 54.9% were boys. It changed hands: since 2023 it has gone mainly to girls, having gone mainly to boys before that. In births since 2016 it is 52% girls and 48% boys.

Counted from every US birth the Social Security Administration recorded under this name, so it reflects use rather than opinion. A name given to fewer than five babies of one sex in a year is withheld at source and is not counted.

Names that peaked alongside Koi

Where Koi is most concentrated

How much more common the name is in each state than across the country as a whole.

Explore further

See Koi on the interactive charts

Source: U.S.A. Social Security Administration. Years 1880–2025. namelegacy.org