Serranilla Bank is a western Caribbean island located about 210 miles north-northeast of Nicaragua. The United States, Colombia (indirectly) and possibly Honduras have all claimed the island. Some believe that the United States acquired the bank under the Guano Islands Act of August 18, 1856.

Several very small cays emerge above the water to form the bank's islands. Overall, the bank is 40 kilometers wide and 32 kilometers long.

Colombia has not directly claimed Serranilla Bank but is on record as considering the bank a part of the Providence Archipelago in the intendancy of San Andres y Providencia. Honduras may have asserted its own claim over Serranilla as well. The U.S. asserts sovereignty over West Breaker, Middle Cay, East Cay and Beacon Cay in particular. If the United States claim is valid, then the Bank would be considered an unorganized, unincorporated United States territory.

See also: Bajo Nuevo Bank, Political divisions of the United States