Waipahu is a former sugarcane plantation town and now census-designated place (CDP) located in the ?Ewa District on the island of O?ahu in the City & County of Honolulu, Hawai?i, United States. As of the 2010 Census, the CDP population was 38,216.
Before the Western civilization set foot in Hawaii, the Hawaiians considered Waipahu to be the capital of Oahu. Royalty in the Kingdom of Hawaii would often gather and enjoy the fresh water from the spring Waipahu. In 1897, Oahu Sugar Company was incorporated, and its board of directors located the sugar mill in Waipahu. It had 943 field workers. In 1932 the Oahu Sugar Co. opened a continuation school, and allowed a half-day off from work once a week for workers to attend. Those who weren't available during the day could also attend evening courses. This was to give them a chance to better their knowledge for a better job.