Kingman Reef is a largely submerged, uninhabited, triangle-shaped reef, geologically an atoll, 9.0 nmi (20 km) east-west and 4.5 nmi (8 km) north-south, in the North Pacific Ocean, roughly halfway between the Hawaiian Islands and American Samoa. It has an area of 3 hectares and is a unincorporated territory of the United States in Oceania. The reef is administered by the United States Fish and Wildlife Service as the Kingman Reef National Wildlife Refuge. It was claimed by the US in 1859, and later used briefly as stopover for commercial Pacific flying boat routes in the 1930s going to New Zealand; however, the route was changed with a different stopover. It was administered by the Navy from 1934 to 2000, and thereafter the Fish and Wildlife service. It has since become a marine protected area. In the 19th century it was noted as maritime hazard, earning the name Hazard Rocks, and is known to have been hit once in 1876. In the 21st century it has been noted for its marine biodiversity and remote nature. There are hundreds of species of fish and coral on and around the reef.

Territories of the United States are sub-national administrative divisions overseen by the federal government of the United States. The various American territories differ from the U.S. states and Indian reservations as they are not sovereign entities. In contrast, each state has a sovereignty separate from that of the federal government and each federally recognized Native American tribe possesses limited tribal sovereignty as a "dependent sovereign nation." Territories are classified by incorporation and whether they have an "organized" government through an organic act passed by the Congress. American territories are under American sovereignty and, consequently, may be treated as part of the United States proper in some ways and not others. Unincorporated territories in particular are not considered to be integral parts of the United States, and the Constitution of the United States applies only partially in those territories.