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 "place of noise", perhaps a reference to the fact that once upon a time, heavy surf on the distant coast could be heard here. The population was 17,821 at the 2010 census. The U.S. postal codes for Wahiawa are 96786 and 96857.