Kingman Reef is a largely submerged, uninhabited triangular shaped reef, 9.5 nautical miles (18 kilometers) east-west and 5 nmi (9 km) north-south, located in the North Pacific Ocean, roughly halfway between the Hawaiian Islands and American Samoa at 6°23′N 162°25′W. It is the northernmost of the Northern Line Islands and lies 36 nautical miles (67 km) northwest of the next closest island (Palmyra Atoll), and 930 nautical miles (1,720 km) south of Honolulu.
The reef encloses a lagoon up to 270 feet (82 m) deep in its western part. The total area within the outer rim of the reef is 29 sq mi (75 km²). There are two small strips of dry land composed of coral rubble and giant clamshells on the eastern rim with areas of 2 and 1 acre (8,100 and 4,000 m²) having a coastline of 2 miles (3 km). The highest point on the reef is less than 5 feet (1.5 m) above sea level, which is wetted or awash most of the time, making Kingman Reef a maritime hazard. It has no natural resources and supports no economic activity.