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 2020 census, the CDP had a population of 4,062. Waialua was one of the six original districts of ancient Hawaii on the island, known as moku. Waialua is a former mill town and residential area, quite different in its quiet ambiance from nearby Haleʻiwa, which is more commercial and tourist oriented.