Given name & surname · also Welsh, Hawaiian
Kai
Kai is used in several naming traditions, with different explanations for the same spelling.
Original GreekΚαΐ
Meaning & origin
What it means
A connection with the sea occurs in Hawaiian interpretations. It should not be applied automatically to the European name.
Where it comes from
The Scandinavian, North German, and Frisian name has an uncertain origin. Hawaiian use provides a separate naming context.
How it developed
For the European form, proposed connections include an Old Norse word for a hen or chicken and the Roman name Gaius. Neither explanation is certain.
The story
Published U.S. birth records include this spelling as early as 1926. This is the earliest published observation available here, rather than a date for the name’s origin.
From dated birth records
Kai through the years
- Babies since 1880
- 78,710
- 70,232 boys · 8,478 girls
- Most popular year
- 2022
- 5,732 babies
- 2025
- 4,002
- #93 for boys · #1,054 for girls
- 2021–25 vs 2016–20
- +31%
- Rising
Boys, girls and both
The balance of boys and girls given this name has shifted over time. Recent births are 93% boys.
Where it’s given
By the numbers
In 2025, this name appeared in 3,768 U.S. birth records for boys, ranking No. 93 among boys’ names. Average annual use for boys was 34.6% higher in 2021–2025 than in 2016–2020. It also appeared in 234 birth records for girls in 2025. In 2025, California had the largest reported state-level birth count for boys with this name (601). Published U.S. population figures for this spelling include 53,204 as a first name in 2020; 1,337 as a surname in 2020.
From Social Security birth records and U.S. Census name counts for this exact spelling. Other spellings are counted separately.
Kai’s family of names
In Estonian usage, Kai is a short form of Catherine. In Faroese usage, Kai developed from the Danish form Kaj. In German usage, Kai has a related form in Kay.
Inner ring: spellings · middle: nicknames and forms · outer: across languages.
Around the world
Kai has relatives in 10 languages. Lines run from its Ancient Greek roots to each of them.
22 related names in 10 languages. Point at a dot, or tab to the map and use the arrow keys.
Nicknames & forms 18
Diminutives, pet forms, short forms and variants used alongside the name.
Spellings & scripts 5
The same name written differently, including transliterations into other scripts.
Across languages 15
Equivalents and cognates in other languages, plus older forms it grew from.
Show 7 moreShow fewer
See also 8
Names our sources mention alongside this one. They are related in story or meaning, not forms of this name.
People named Kai
- Kai SiegbahnSwedish physicist (1918–2007)
- Kai HavertzGerman association football player (born 1999)
- Kai HansenGerman guitarist and singerborn 1963
- Zou KaiChinese artistic gymnastborn 1988
- Kai WegnerGerman politicianborn 1972
- Kai CenatAmerican internet personality and online streamer (born 2001)
- Kai ShibatoJapanese association football playerborn 1995
- Liang KaiChinese artist1200–1300
- Kai WindingDanish-born American jazz composer and trombonist1922–1983
Listed by how widely each person is written about, which says nothing about the name itself.
Similar names
If you love Kai, these share its style, era, origin or sound, from outside its own family.
Leith
“from the broad river”
>99% boys
Zale
“one who has the strength of the sea” · “having the strength of the sea”
>99% boys
Jolan
“resembling a violet flower”
>99% boys
Acacio
“of the thorny tree”
98% boys · 2% girls
Glain
“as precious as jewel”
75% boys · 25% girls
Paio
“of the sea”
>99% boys
Bardhyl
“white star” · “white”
99% boys · 1% girls
Pelagios
“man of the sea”
>99% boys