Kapaʻa (Kauaʻi dialect: Tapaʻa) is an unincorporated community and census-designated place (CDP) in Kauaʻi County, Hawaiʻi, United States. The population was 10,699 at the 2010 census, up from 9,471 at the 2000 census.
Kapaʻa is a Hawaiian adjective meaning "solid".
Kapaʻa is located on the east side of the island of Kauai at 22°5′18″N 159°20′16″W (22.088281, -159.337706). It is bordered to the south by the communities of Wailua and Wailua Homesteads and to the east by the Pacific Ocean. Hawaii Route 56 passes through the eastern part of the community, leading north 6 miles (10 km) to Anahola and south 8 miles (13 km) to Lihue.
According to the United States Census Bureau, the Kapaa CDP has a total area of 10.3 square miles (26.8 km2). 10.0 square miles (25.9 km2) of it are land and 0.35 square miles (0.9 km2) of it (3.27%) are water.
As of the census of 2000, there were 9,471 people, 3,129 households, and 2,281 families residing in the CDP. The population density was 971.2 inhabitants per square mile (375.1/km2). There were 3,632 housing units at an average density of 372.4 per square mile (143.8/km2). The racial makeup of the CDP was 27.8% White, 0.3% Black, 0.5% Native American, 31.7% Asian, 10.0% Pacific Islander, 1.0% from other races, and 28.7% from two or more races. Hispanic or Latino of any race were 9.5% of the population.