Waialua is a census-designated place and North Shore community in the Waialua District on the island of Oʻahu, City & County of Honolulu, Hawaii, United States. As of the 2010 Census, the CDP had a population of 3,860.
Waialua was one of the six original districts of ancient Hawaii on the island, known as moku. Waialua is a former (sugar) mill town and residential area, quite different in its quiet ambiance from nearby Haleʻiwa, which is more commercial and tourist oriented. The Waialua Sugar Mill is the center of this town and the historical base of its plantation history.
The U.S. postal code for Waialua is 96791.
Waialua is located at 21°34'31" North, 158°7'46" West (21.575300, -158.129457), southwest of Haleʻiwa, reached on Waialua Beach Road (State Rte. 82) or Kaukonahua Road (State Rte. 830). Kaukonahua Road turns eastward and, as State Rte. 803 then 801 runs up into the central plateau of Oʻahu to Wahiawā or (as 803) to Schofield Barracks.