Kapolei is a planned community in Honolulu County, Hawaiʻi, United States, on the island of Oʻahu. It is colloquially known as the "second city" of Oʻahu, in relation to Honolulu. For statistical purposes, the United States Census Bureau has defined Kapolei as a census-designated place (CDP) within the consolidated city-county of Honolulu.

Honolulu County, officially known as the City and County of Honolulu, is a consolidated city-county in the U.S. state of Hawaii. The city-county includes both Urban Honolulu and the rest of the neighborhoods on the island of Oʻahu, as well as several minor outlying islands, including all of the Northwestern Hawaiian Islands except Midway Atoll.