Mililani is a census-designated place (CDP) and master planned community located near the center of the island of Oʻahu in Honolulu County, Hawaii, United States. It had a population of 28,608 at the 2000 census.
Mililani sits on former plantation fields owned by Castle & Cooke, which began planning for its development in the early 1960s under its Oceanic Properties subsidiary. Castle & Cooke's plan was to make Mililani Town a satellite city by using a prestigious group of planners and architects to satisfy Oahu's great pent-up demand for housing with a sensitively designed, affordable new community of a type unique in Hawaii. The first homes in Mililani went on sale on June 3, 1968.