Navassa is a pear-shaped island in the Caribbean Sea between Haiti and Jamaica about 100 miles south of Guantanamo Bay, Cuba.

Navassa was discovered by Peter Duncan, who claimed the island for the United States in 1857, under the Guano Islands Act of 1856.

Navassa Island has come to the attention of the Supreme Court through two cases, the better-known of which, Jones v. United States, involved the question of whether a federal court in the United States had jurisdiction over a crime committed on Navassa.

The Guano Islands Act provides that guano islands claimed on behalf of the United States may "be considered as appertaining to the United States," and that any crime committed on such an island would be deemed as having been committed on the high seas on board a U.S. vessel and be punished according to the laws of the United States