| Official Name: | Wailua, Kauai County, Hawaii |
| Settlement Type: | Census-designated place |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Hawaii |
| Subdivision Type2: | County |
| Subdivision Name2: | Kauai |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 4.77 |
| Area Land Km2: | 3.98 |
| Area Water Km2: | 0.80 |
| Area Total Sq Mi: | 1.84 |
| Area Land Sq Mi: | 1.54 |
| Area Water Sq Mi: | 0.31 |
| Population As Of: | 2020 |
| Population Total: | 2359 |
| Population Density Km2: | 593.14 |
| Population Density Sq Mi: | 1535.81 |
| Timezone: | Hawaii-Aleutian |
| Utc Offset: | -10 |
| Coordinates: | 22.0586°N -159.3417°W |
| Elevation M: | 6 |
| Elevation Ft: | 20 |
| Area Code: | 808 |
| Blank Name: | FIPS code |
| Blank Info: | 15-77000 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 0364739 |
Wailua (literally, "two waters" in Hawaiian[2]) is a census-designated place (CDP) in Kauaʻi County, Hawaiʻi, United States. The population was 2,359 at the 2020 census,[3] up from 2,083 at the 2000 census.
Wailua is located at 22.0586°N -159.3417°W (22.058631, -159.341761),[4] on the east side of the island of Kauai. It is bordered to the north by Kapaa, to the west by the Wailua Homesteads CDP, to the south by the Wailua River, and to the east by the Pacific Ocean.
Nounou Mountain, also known as the "Sleeping Giant", is about tall and divides coastal Wailua (the Wailua CDP) from inland Wailua (the Wailua Homesteads CDP). Inland Wailua is often referred to as a bedroom community, since it is home to many, but lacks any commercial or government facilities. Coastal Wailua is a significant commercial center, with many hotels and condominiums for visitors. The Wailua River is the only navigable river in the state of Hawaiʻi and is a center of activity for locals (water skiing, kayaking) and visitors (boat tour of Fern Grotto).
According to the United States Census Bureau, the Wailua CDP has an area of 4.6km2, of which 3.8km2 is land and 0.8km2, or 17.27%, is water.[3]
As of the census[5] of 2000, there were 2,083 people, 781 households, and 549 families residing in the CDP. The population density was 1618.6sp=usNaNsp=us. There were 1,211 housing units at an average density of 941sp=usNaNsp=us. The racial makeup of the CDP was 29.7% White, 0.8% African American, 0.5% Native American, 34.8% Asian, 8.5% Pacific Islander, 0.6% from other races, and 25.1% from two or more races. Hispanic or Latino of any race were 7.1% of the population.
There were 781 households, out of which 30.7% had children under the age of 18 living with them, 52.1% were married couples living together, 12.4% had a female householder with no husband present, and 29.7% were non-families. 23.8% of all households were made up of individuals, and 8.1% had someone living alone who was 65 years of age or older. The average household size was 2.67 and the average family size was 3.16.
In the CDP the population was spread out, with 25.4% under the age of 18, 6.2% from 18 to 24, 25.3% from 25 to 44, 25.6% from 45 to 64, and 17.4% who were 65 years of age or older. The median age was 41 years. For every 100 females, there were 102.0 males. For every 100 females age 18 and over, there were 98.2 males.
The median income for a household in the CDP was $45,875, and the median income for a family was $52,083. Males had a median income of $34,615 versus $25,380 for females. The per capita income for the CDP was $20,231. About 8.7% of families and 8.9% of the population were below the poverty line, including 9.5% of those under age 18 and none of those age 65 or over.