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 2000 Census, the CDP had a total population of 3,664.
Waimānalo is close to, but somewhat separate from the neighborhood of Waimānalo Beach. Waimānalo has a small commercial center along Kalanianaʻole Highway, but is separated from the shoreline and Waimānalo Beach (the longest stretch of sandy shoreline on Oʻahu) by Bellows Air Force Station. Waimānalo is noteworthy for its local flavor and large agricultural lots in the valley that extend back towards the Koʻolau from the center of town. Numerous plant nurseries are found in this area.