Wahiawa (Hawaiian: Wahiawā) is a census-designated place (CDP) in Honolulu County, Hawaii, United States, on the island of Oahu. It is located in the Wahiawa District, on the plateau or "central valley" between the two volcanic mountains that comprise the island. In Hawaiian, wahi a wā means "space of the wa people". The population was 17,821 at the 2010 census.
Lakes and reservoirs are rare in Hawaii, and Wahiawa is at once unique in being surrounded on three sides by Lake Wilson (also known as Wahiawa Reservoir or Kaukonahua). The town must be accessed by either of two bridges on Kamehameha Highway (State Rte. 80) across the narrow north and south arms of the reservoir. Outside of the reservoir, the town used to be surrounded by military bases and agricultural fields, but development is making its way up from the increasingly urbanized southern portion of the central plain. Still, there are significant U.S. Army facilities here, including Schofield Barracks, Wheeler Army Airfield, and East Range, an Army training area extending into the hills south and east of town. Schofield Barracks alone is larger than Wahiawa. Wahiawa is also the home of the U.S. Navy's Naval Computer and Telecommunications Area Master Station Pacific.
The U.S. postal codes for Wahiawa are 96786 and 96857.