Kai

♀ Girl

Pronounced KY /kaɪ/High

Meaning: Sea; from Hawaiian kai (sea, ocean)Medium

In 30 seconds: A one-syllable name found across multiple cultures: 'sea' in Hawaiian, 'earth' or 'pioneer' in Japanese, and the Greek letter chi (χ). As a girls' name it is part of the ultra-short name trend alongside Zia, Rue, and Bo.

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Origin MediumHawaiian, Greek, Japanese

MeaningSea; from Hawaiian kai (sea, ocean)

U.S. rank (2025)#1054 ↗ Rising

2025 U.S. births234 girls (0.01% of U.S. girls)

Peak year2021

Total births (all-time)≈ 8,477

Popularity in the U.S. · SSA data

U.S. births per year (Social Security Administration, 1880–present). Pink marker = peak year.

SSA data updated May 2026. How we source & verify this data.

History & Origin

Kai exists independently in multiple languages. In Hawaiian it means 'sea.' In Japanese it can mean 'earth,' 'shell,' or 'pioneer' depending on the kanji. The name also appears in Scandinavian as a form of Kaius or Cai (rejoice), in Welsh as a form of Kay/Cai, and in Chinese contexts.

Kai has been appearing in U.S. birth data for both sexes from the late 20th century. For girls it has been growing since the 2010s. It ranked #1133 for girls in 2024.

Did you know? Kai is one of the world's most linguistically widespread names — it has independent meanings in Hawaiian, Japanese, Chinese, Maori, Finnish, Scandinavian, Welsh, and even Zulu, making it a true cross-cultural phenomenon.

Overall data confidence 82%

Behind the Name — Kai — multiple etymologiesU.S. Social Security Administration — popularity data

Variations

KaiaKayCai

Nicknames

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Famous Bearers

★Kai Cole
American architect and producer

If you like Kai…

Kaia— the longer form of Kai with the same Hawaiian roots

Rue— one-syllable nature name in the same minimalist category

Zia— one-syllable Z-name with the same ultra-short, vibrant feel

Wren— one-syllable nature name in the same crisp single-syllable trend

Explore names like Kai

By themeunisex short japanese hawaiian one-syllable multicultural sea

By meaningSea / Water

All themes →All meanings →All origins →

Frequently Asked

What does the name Kai mean?

Kai means 'sea' in Hawaiian and has independent meanings in multiple languages: 'earth' in Japanese, a form of 'rejoice' in Scandinavian, and others.

How do you pronounce Kai?

It's said KY — one syllable, rhyming with 'sky.'

Is Kai a boy or girl name?

Kai is a well-established unisex name used for both boys and girls.

How popular is Kai?

Kai ranked #1133 for U.S. girls in 2024.