Kauaʻi County (Hawaiian: Kalana o Kauaʻi), officially known as the County of Kauaʻi, is a county in the U.S. state of Hawaiʻi. It encompasses the islands of Kauaʻi, Niʻihau, Lehua, and Kaʻula. According to the 2020 Census, the population was 73,298. The county seat is Līhuʻe.

The Kapa'a Micropolitan Statistical Area includes all of Kauai County.

According to the U.S. Census Bureau, the county has a total area of 1,266 square miles (3,280 km), of which 620 square miles (1,600 km) is land and 646 square miles (1,670 km) (51.0%) is water. The Pacific Ocean surrounds the county.

• Honolulu County, Hawaii - southeast
• Midway Atoll - northwest

• Hanalei National Wildlife Refuge
• Huleia National Wildlife Refuge
• Kilauea Point National Wildlife Refuge

Kauaʻi County operates under a mayor-council form of municipal government. The Mayor of Kauaʻi, elected by the voters on a nonpartisan basis, holds executive authority for a four-year term. Meanwhile, legislative authority is vested in the seven-member County Council. Members of the County Council are elected on a nonpartisan, at-large basis to two-year terms.

Kauai County, like the rest of Hawaii, is represented entirely by Democrats in both the United States Senate and the United States House of Representatives.

Senators		Name	Party	First Elected	Level
	Senate Class 1	Mazie Hirono	Democratic	2013	Junior Senator
	Senate Class 3	Brian Schatz	Democratic	2012	Senior Senator
Representatives		Name	Party	First Elected	Area(s) of Kauai County Represented
	District 2	Jill Tokuda	Democratic	2023	entire county

District		Name	Party	First Elected	Area(s) of Kauaʻi County Represented
	8	Ron Kouchi	Democratic	2010	entire county

District		Name	Party	First Elected	Area(s) of Kauaʻi County Represented
	15	Nadine Nakamura	Democratic	2016	Hā‘ena, Wainiha, Hanalei, Princeville, Kīlauea, Anahola, Keālia, Kāpa‘a, portion of Wailuā, Kawaihau
	16	Luke Evslin	Democratic	2023	Wailuā, Hanamāʻulu, Kapaia, Līhuʻe, Puhi, portion of ʻŌmaʻo
	17	Dee Morikawa	Democratic	2011	Niʻihau, portion of ʻŌmaʻo, Kōloa, Po‘ipū, Lāwa‘i, Kalāheo, ‘Ele‘ele, Hanapēpē, Kaawanui Village, Pākalā Village, Waimea, Kekaha

Kauai County has traditionally been a solid Democratic stronghold. The county has not voted Republican since the 1984 federal election, when it narrowly voted in favor of Ronald Reagan. In 2024, while it still voted majority Democratic, Kauai County cast the highest percentage of its vote for the Republican candidate out of any county in the state, a record that has generally been held by Honolulu County. This was the first time since 1960 that the county held this distinction.

United States presidential election results for Kauai County, Hawaii

Year	Republican		Democratic		Third party(ies)
	No.	%	No.	%	No.	%
2024	11,803	39.26%	17,675	58.79%	586	1.95%
2020	11,582	34.58%	21,225	63.36%	690	2.06%
2016	7,574	28.76%	16,456	62.49%	2,305	8.75%
2012	6,121	24.13%	18,641	73.47%	610	2.40%
2008	6,245	22.94%	20,416	74.99%	563	2.07%
2004	9,740	39.15%	14,916	59.96%	220	0.88%
2000	6,583	30.23%	13,470	61.87%	1,720	7.90%
1996	5,325	25.33%	13,357	63.54%	2,338	11.12%
1992	6,274	32.80%	10,715	56.02%	2,138	11.18%
1988	8,298	40.95%	11,770	58.08%	198	0.98%
1984	9,249	50.45%	8,862	48.34%	221	1.21%
1980	5,883	35.39%	9,081	54.64%	1,657	9.97%
1976	6,278	43.23%	8,105	55.81%	139	0.96%
1972	7,571	58.36%	5,401	41.64%	0	0.00%
1968	4,140	36.49%	7,051	62.15%	155	1.37%
1964	1,971	18.45%	8,713	81.55%	0	0.00%
1960	5,655	54.95%	4,636	45.05%	0	0.00%

Historical population

Census	Pop.	Note	%±
1900	20,734		—
1910	23,952		15.5%
1920	29,438		22.9%
1930	35,942		22.1%
1940	35,818		−0.3%
1950	29,905		−16.5%
1960	28,176		−5.8%
1970	29,761		5.6%
1980	39,082		31.3%
1990	51,177		30.9%
2000	58,463		14.2%
2010	67,091		14.8%
2020	73,298		9.3%
2023 (est.)	73,851		0.8%
U.S. Decennial Census 1790-1960 1900-1990 1990-2000 2010-2018

At the 2000 census there were 58,463 people, 20,183 households, and 14,572 families in the county. The population density was 94 people per square mile (36 people/km). There were 25,331 housing units at an average density of 41 per square mile (16/km). The racial makeup of the county was 36.0% Asian, 29.5% White, 23.8% from two or more races, 9.1% Pacific Islander, 0.3% Black or African American, 0.4% Native American and 0.9% from other races. 8.2%. were Hispanic or Latino of any race.

Of the 20,183 households 34.0% had children under the age of 18 living with them, 53.9% were married couples living together, 12.8% had a female householder with no husband present, and 27.8% were non-families. 21.4% of households were one person and 7.7% were one person aged 65 or older. The average household size was 2.87 and the average family size was 3.34.

The age distribution was 26.4% under the age of 18, 7.1% from 18 to 24, 27.2% from 25 to 44, 25.5% from 45 to 64, and 13.8% 65 or older. The median age was 38 years. For every 100 females there were 100.10 males. For every 100 females age 18 and over, there were 97.50 males.

According to the county's 2022 Annual Comprehensive Financial Report, the top non-government employers in the county are the following:

#	Employer	# of Employees
1	Wilcox Health (Wilcox Medical Center)	846
2	Grand Hyatt Kauai Resort and Spa	810
3	Ohana Pacific Management Co.	371
4	Kauai Veterans Memorial Hospital	275
5	Kauai Beach Resort	160
6	Samuel Mahelona Memorial Hospital	148
7	Kauaʻi Island Utility Cooperative	140
8	Kauai Nursery & Landscaping Inc.	97
9	Gather FCU	88
10	The Parrish Collection	85

Kauai Community College is the county's only institution of higher education. One of the ten branches of the University of Hawaiʻi system, it offers a range of 2-year degrees and is accredited by the Western Association of Schools and Colleges.

Public schools in the county are operated by the Hawaiʻi State Department of Education, and the county is represented by Maggie Cox on the state's Board of Education. There are 10 elementary schools, 3 middle schools, 3 high schools, and 5 K-12 schools in the county.

• Kapa'a High School
• Kauaʻi High School
• Waimea High School

• Chiefess Kamakahelei Middle School
• Kapa'a Middle School
• Waimea Canyon Middle School

• Alakaʻi O Kauaʻi Public Charter School
• Eleele Elementary School
• Hanalei Elementary School
• Kalaheo Elementary School
• Kapa'a Elementary
• Kaumualii Elementary School
• Kekaha Elementary School
• Kilauea Elementary School
• Kōloa Elementary School
• Wilcox Elementary School

• Kanuikapono Public Charter School
• Kawaikini New Century Public Charter School
• Ke Kula Niʻihau O Kekaha Learning Center
• Kula Aupuni Niʻihau A Kahelelani Aloha
• Ni'ihau High & Elementary

There are four private schools in the county: Island School, Kahili Adventist School, St. Theresa's Elementary School, and ʻŌlelo Christian Academy. St. Catherine's School used to operate, but closed its doors on June 7, 2024.

Lihue Airport serves the island of Kauai. Bus service is provided by The Kauai Bus.

Major Highways

• Route 50
• Route 51
• Route 56
• Route 58
• Route 520
• Route 540
• Route 550
• Route 570
• Route 580
• Route 581
• Route 583

There are no incorporated communities in Kauai County, or in any other county of Hawaii. The county is the only form of local government in the State of Hawaii.

• Puuwai
• Kealia

Kauai County's sister cities are:

22°04′N 159°39′W / 22.067°N 159.650°W / 22.067; -159.650