Interstate H-1 (H-1) is the longest and busiest Interstate Highway in the US state of Hawaii. The highway is located on the island of Oʻahu. Despite the number, this is an east–west highway; the 'H'-series numbering reflects the order in which routes were funded and built. H-1 goes from Route 93 in Kapolei to Route 72 in Kāhala. East of Middle Street in Honolulu (exit 19A), H-1 is also known as the Lunalilo Freeway, after the former Hawaiian king, and is sometimes signed as such at older signs in central Honolulu. West of Middle Street, H-1 is also known as the Queen Liliʻuokalani Freeway, after the former Hawaiian queen; this name is shown on some roadmaps. It is both the southernmost and westernmost signed Interstate Highway located in the US.

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.