Kahuku is a census-designated place (CDP) in the Koʻolauloa District on the island of Oahu, County of Honolulu, Hawaii, United States. In the Hawaiian language, ka huku means "the projection", presumably a reference to Kahuku Point nearby, the northernmost point of land on the island of Oahu. As of the 2000 Census, Kahuku had a total population of 2,097.
Kahuku is located at 21°40′49″N 157°57′1″W / 21.68028°N 157.95028°W / 21.68028; -157.95028. This community is located northwest from Laie and east from Kuilima and Kawela Bay along Kamehameha Highway (Route 83).
According to the United States Census Bureau, the CDP has a total area of 2.3 square miles (5.9 km²), of which, 1.0 square miles (2.5 km²) of it is land and 1.3 square miles (3.4 km²) of it is water. The total area is 57.46% water, the Pacific Ocean lying off the coast in the census tract.