Kai is a boys' name of Hawaiian origin, meaning “sea”, Hawaiian, but also an independent Scandinavian, Frisian and Welsh name. Has several independent sources: Hawaiian kai, sea; a Frisian and Scandinavian name; and Welsh Cai, Sir Kay of Arthurian legend.

Kai

Gender: Boy
Say it: KY
Origin: Hawaiian
UK rank, 2025: #70 for boys
US rank, 2025: #93 for boys

Classic

Kai is a boys' name of Hawaiian origin, meaning “sea”. In 2025 it ranked 70th for boys in the UK (816 babies) and 93rd for boys in the US (3,768 babies).

What does Kai mean?

Hawaiian: Hawaiian, but also an independent Scandinavian, Frisian and Welsh name

“sea”

Has several independent sources: Hawaiian kai, sea; a Frisian and Scandinavian name; and Welsh Cai, Sir Kay of Arthurian legend.

Is Kai a girl's or a boy's name?

Kai is a boys' name. In 2025, it was given to 4 girls and 816 boys in the UK and 234 girls and 3,768 boys in the US.

How popular is Kai in the UK?

Rank in 2025: #70among boys
Babies in 2025: 816about 1 in 370 boys
Five-year trend: Steadyup 17% in five years
Same name in a class: 3.7%chance among 15 boys

In 2025, 816 boys in the UK were named Kai, making it the 70th most popular name for boys. Five years earlier, in 2020, it was 95th. Its busiest year was 2010, with 1,562 boys. 4 girls were also named Kai in 2025 (4,935th for girls).

It has been given to fewer boys each year for the last 3 years.

Half of all the boys named Kai in the UK since 1996 were born between 2005 and 2016, the years shaded on the chart below.

In 2025, 909 boys in the UK were given Kai or a name that sounds the same. With every name's spellings counted this way, that ranks #64, up from #70 for this spelling alone.

Kai 816
Cai 55
Khai 22
Kye 16

Among boys in 2025, it was 78th in England and Wales, 40th in Scotland and 44th in Northern Ireland.

In the England and Wales top 100 for boys, which the ONS has published every ten years since 1904: 2004 (#62), 2014 (#77) and 2024 (#72).

1996Busiest: 1,562 in 20102025

Kai in the UK, year by year

Year	Boys	Rank
2025	816	#70
2024	856	#70
2023	860	#73
2022	973	#65
2021	796	#81
2020	711	#95
2019	682	#103
2018	762	#95
2017	815	#93
2016	940	#83
2015	927	#84
2014	1,024	#77
2013	1,255	#56
2012	1,273	#62
2011	1,445	#55
2010	1,562	#53
2009	1,202	#66
2008	1,225	#65
2007	1,385	#64
2006	1,366	#62
2005	1,154	#67
2004	1,180	#65
2003	1,271	#55
2002	1,137	#63
2001	1,003	#67
2000	775	#77
1999	640	#96
1998	569	#106
1997	421	#118
1996	227	#160

How popular is Kai in the US?

Rank in 2025: #93among boys
Babies in 2025: 3,768about 1 in 450 boys
Five-year trend: Steadyup 18% in five years
Same name in a class: 3%chance among 15 boys

In 2025, 3,768 boys in the US were named Kai, making it the 93rd most popular name for boys. Five years earlier, in 2020, it was 93rd. Its busiest year was 2022, with 5,374 boys. It first appears in the records in 1926. 234 girls were also named Kai in 2025 (1,053rd for girls).

It has been given to fewer boys each year for the last 3 years. 2025 had fewer boys named Kai than any year since 2019.

Half of all the boys named Kai in the US since 1880 were born between 2010 and 2022, the years shaded on the chart below.

In 2025, 4,193 boys in the US were given Kai or a name that sounds the same. With every name's spellings counted this way, that ranks #90, up from #93 for this spelling alone.

Kai 3,768
Khai 175
Kye 136
Cai 69
Ky 31
Kaii 9
Kaj 5

Girls were 21% of the babies named Kai in the US in 1959, and 6% in 2025.

1926Busiest: 5,374 in 20222025

Kai in the US, year by year

Year	Boys	Rank
2025	3,768	#93
2024	4,301	#76
2023	4,976	#61
2022	5,374	#59
2021	4,641	#70
2020	3,867	#93
2019	3,744	#100
2018	3,463	#112
2017	3,158	#126
2016	2,895	#145
2015	2,852	#145
2014	2,411	#177
2013	1,983	#199
2012	1,938	#197
2011	1,790	#202
2010	1,750	#205
2009	1,759	#213
2008	1,609	#229
2007	1,399	#252
2006	1,451	#238
2005	1,413	#239
2004	1,324	#248
2003	1,217	#264
2002	1,108	#276
2001	718	#370
2000	622	#403
1999	465	#478
1998	363	#548
1997	322	#575
1996	297	#598
1995	357	#534
1994	216	#709
1993	182	#781
1992	159	#834
1991	155	#827
1990	124	#922
1989	140	#845
1988	93	#1,011
1987	105	#920
1986	96	#931
1985	99	#910
1984	85	#959
1983	75	#1,022
1982	94	#920
1981	88	#959
1980	83	#989
1979	87	#945
1978	74	#1,005
1977	66	#1,064
1976	54	#1,163
1975	58	#1,099
1974	50	#1,171
1973	53	#1,123
1972	52	#1,129
1971	40	#1,330
1970	58	#1,070
1969	46	#1,152
1968	47	#1,083
1967	40	#1,180
1966	36	#1,258
1965	33	#1,334
1964	32	#1,383
1963	35	#1,317
1962	29	#1,453
1961	23	#1,685
1960	20	#1,811
1959	26	#1,558
1958	20	#1,765
1957	16	#2,018
1956	12	#2,359
1955	22	#1,645
1954	14	#2,113
1953	10	#2,530
1952	5	#3,731
1951	14	#2,054
1950	9	#2,579
1949	5	#3,688
1948	0	–
1947	0	–
1946	0	–
1945	0	–
1944	5	#3,428
1943	0	–
1942	0	–
1941	0	–
1940	0	–
1939	0	–
1938	0	–
1937	0	–
1936	0	–
1935	0	–
1934	0	–
1933	0	–
1932	6	#3,360
1931	0	–
1930	0	–
1929	0	–
1928	0	–
1927	0	–
1926	6	#3,706

Names like Kai

Names given in the same years and the same naming tradition, with a similar sound.

Koa Yusuf Dylan Ethan Finn Logan Mason Jude Kian Ibrahim Lucas Musa

Other spellings of Kai

Cai Khai Kye Ky Kaii Kaj

Names related to Kai

Kaio Ka Kaia Kaiya Kaiah Khaia Kaiyu

More Hawaiian names

Leilani Kailani Kalani Nalani Makai Keanu Koah Meilani Kailany Leilany Laylani Kaleo Lani Luana Leylani Lailani

Every Hawaiian name

Sources

Figures from Baby names in England and Wales (Office for National Statistics), Babies' first names (National Records of Scotland), Baby names (Northern Ireland Statistics and Research Agency) and Popular Baby Names (US Social Security Administration). Nameling last updated them on 20 October 2026. How the figures are worked out, and the data to download.

To cite this page: Nameling, “Kai: name meaning, origin and popularity”, https://www.nameling.co.uk/names/kai, updated 20 October 2026.