Kalāheo is an unincorporated census-designated place in Kauaʻi County, island of Kauaʻi, Hawaiʻi, United States. The population was 4,595 at the 2010 census.The National Tropical Botanical Garden is located in Kalāheo.Kalāheo is located at 21°55′28″N 159°31′46″W / 21.92444°N 159.52944°W / 21.92444; -159.52944.According to the United States Census Bureau, the CDP has a total area of 3.0 square miles, of which 2.9 square miles of it is land and 0.1 square miles of it is water.As of the census of 2000, there were 3,913 people, 1,428 households, and 1,039 families residing in the CDP. The population density was 1,328.5 people per square mile. There were 1,509 housing units at an average density of 512.3 per square mile. The racial makeup of the CDP was 40.0% White, 0.2% African American, 0.2% Native American, 29.6% Asian, 3.9% Pacific Islander, 1.2% from other races, and 24.9% from two or more races. Hispanic or Latino of any race were 11.5% of the population.