Mililani () is a city located near the center of the island of Oahu in Honolulu County, Hawaiʻi, United States. It consists of two census-designated places, Mililani Town, with a population of 28,121 at the 2020 census, and Mililani Mauka, with a 2020 census population of 21,075. History Mililani sits on former plantation fields owned by Castle & Cooke, which began planning for its development in 1958 under its Oceanic Properties subsidiary. Castle & Cooke's plan was to collaborate with planners and architects on making Mililani Town a satellite city that would satisfy Oʻahu's pent-up demand for housing with a new affordable community. It was planned to eventually support a population of 75,000 people. Architect and developer Al Boeke, who would later create the planned community of Sea Ranch, California, was the development director of Mililani. The first homes in Mililani went on sale on June 23, 1968. In 1976, Interstate H-2 opened for Mililani, cutting travel time from Mililani to Honolulu in half. In 1986, Mililani was named an All-America City in recognition of a community effort to clean up drinking water contaminated with agricultural pesticides. It is the only community in Hawaiʻi ever to receive this distinction. On April 6, 1990, ground was broken for Mililani Mauka, a newer and more upscale community east of the Interstate H-2. The first homeowners moved into Mauka in 1992. In 2003, Mililani was designated as the pilot site for the City and County of Honolulu's curbside recycling program. In 2005, Money magazine named Mililani as one of the best places to live in the U.S. In 2006, Mililani ʻIke Elementary School first grade teacher Phyllis Nakama-Kawamoto was named Hawaiʻi's American Star of Teaching by the U.S. Department of Education. Description Mililani is the third wealthiest zip code (96789) in the state of Hawaiʻi, according to the 2006 ranking by Pacific Business News. Although it is largely a bedroom community for Honolulu, Mililani has its own commercial shopping centers, schools (such as Mililani High School), parks, community centers, and a golf course. Mililani homeowners must pay dues to the Mililani Town Association, which enforces covenants and design standards, and provides recreational facilities including several pools. The Mililani Golf Club is a par-72, 6,455-yard course that is open to the public. The Mililani Technology Park is a nearby campus-like park that is zoned for high-tech industries. The older portion of Mililani to the