Jarvis Island is an uninhabited 4.5 km2 (1.7 sq mi) coral island located in the South Pacific Ocean, about halfway between Hawaii and the Cook Islands. It is an unincorporated, unorganized territory of the United States, administered by the United States Fish and Wildlife Service of the United States Department of the Interior as part of the National Wildlife Refuge system. Unlike most coral atolls, the lagoon on Jarvis is wholly dry.

A coral island is a type of island formed from coral detritus and associated organic material. It occurs in tropical and sub-tropical areas, typically as part of a coral reef which has grown to cover a far larger area under the sea. The term low island can be used to distinguish such islands from high islands, which are formed through volcanic action. Low islands are formed as a result of sedimentation upon a coral reef or of the uplifting of such islands.