Lāwaʻi is a census-designated place (CDP) in Kauaʻi County in the U.S. state of Hawaiʻi. The population was 2,363 at the 2010 census, up from 1,984 at the 2000 census.
Lāwaʻi is located on the southern side of the island of Kauai at 21°55′31″N 159°30′27″W / 21.92528°N 159.50750°W / 21.92528; -159.50750 (21.925343, -159.507385). It is bordered to the west by Kalaheo and to the east by Omao. Hawaii Route 50 passes through Lawai, leading northeast 11 miles (18 km) to Lihue and west 6 miles (10 km) to Hanapepe.
According to the United States Census Bureau, the Lawai CDP has a total area of 4.2 square miles (10.8 km), of which 4.1 square miles (10.5 km) are land and 0.1 square miles (0.3 km), or 2.33%, are water.
As of the census of 2000, there were 1,984 people, 711 households, and 531 families residing in the CDP. The population density was 521.7 people per square mile (201.6/km²). There were 747 housing units at an average density of 196.4 per square mile (75.9/km²). The racial makeup of the CDP was 35.4% White, 0.3% African American, 0.3% Native American, 30.8% Asian, 5.5% Pacific Islander, 1.4% from other races, and 26.4% from two or more races. Hispanic or Latino of any race were 11.8% of the population.
There were 711 households out of which 32.2% had children under the age of 18 living with them, 60.6% were married couples living together, 9.1% had a female householder with no husband present, and 25.3% were non-families. 18.8% of all households were made up of individuals and 6.2% had someone living alone who was 65 years of age or older. The average household size was 2.79 and the average family size was 3.18.
In the CDP the population was spread out with 24.8% under the age of 18, 7.1% from 18 to 24, 27.7% from 25 to 44, 27.0% from 45 to 64, and 13.4% who were 65 years of age or older. The median age was 39 years. For every 100 females, there were 105.8 males. For every 100 females age 18 and over, there were 104.2 males.
The median income for a household in the CDP was $55,662, and the median income for a family was $60,750. Males had a median income of $34,479 versus $30,761 for females. The per capita income for the CDP was $22,884. About 2.7% of families and 4.9% of the population were below the poverty line, including 4.0% of those under age 18 and 0.8% of those age 65 or over.