Key West is an island in the Straits of Florida on the North American continent at the southernmost tip of the Florida Keys.

Key West is politically within the limits of the city of Key West, Monroe County, Florida, United States. The city also occupies nearby islands and portions of nearby islands.

The island is about 4 miles (6.4 km) long and 2 miles (3.2 km) wide. In the late 1950s many of the large salt ponds on the eastern side were filled in, nearly doubling the original land mass of the island.