Waimānalo is a census-designated place (CDP) in the City & County of Honolulu, in the District of Koolaupoko on the island of , Hawaii, United States. This small windward community is located near the eastern end of the island. In the Hawaiian language Waimānalo means "potable water"; it is so named for the many brackish ponds in the area that were used for irrigation. As of the 2010 Census, the CDP had a population of 5,451.
Waimānalo is close to, but somewhat separate from, the neighborhood of Waimānalo Beach. Waimānalo has a small commercial center along Kalanianaole Highway, but is separated from the shoreline and Waimānalo Beach (the longest stretch of sandy shoreline on ) by Bellows Air Force Station. Waimānalo is noteworthy for its local flavor and large agricultural lots in the valley that extend back towards the Koolau from the center of town. Numerous plant nurseries are found in this area. There are no hotels in Waimānalo.
Waimānalo is the site of Sea Life Park, located near on Kalanianaole Highway. The U.S. postal code for Waimānalo is 96795.