Kapolei is a planned community located on the island of Oʻahu in the City and County of Honolulu, Hawaiʻi, United States. It is officially defined by the United States Census Bureau as a census-designated place (CDP) within the consolidated city-county of Honolulu.
In 1977, the government designated Kapolei as the "second city" of Oʻahu in relation to Honolulu. As of the 2020 census, the community had a population of 21,411 residents.