Florida is a state in the Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia to the north, the Atlantic Ocean to the east; and the Straits of Florida and Cuba to the south. About two-thirds of Florida occupies a peninsula between the Gulf of Mexico and the Atlantic Ocean. It has the longest coastline in the contiguous United States, spanning approximately 1,350 miles (2,170 km), not including its many barrier islands. It is the only state that borders both the Gulf of Mexico and the Atlantic Ocean. With a population of over 21 million, it is the third-most populous state in the United States and ranks eighth in population density as of 2020. Florida spans 65,758 square miles (170,310 km2), ranking 22nd in area among the states. The Miami metropolitan area, anchored by the cities of Miami, Fort Lauderdale, and West Palm Beach, is the state's largest metropolitan area, with a population of 6.138 million; the most populous city is Jacksonville. Florida's other major population centers include Tampa Bay, Orlando, Cape Coral, and the state capital of Tallahassee.

The Gulf of Mexico is an ocean basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States; on the southwest and south by the Mexican states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatán, and Quintana Roo; and on the southeast by Cuba. The Southern U.S. states of Texas, Louisiana, Mississippi, Alabama, and Florida, which border the gulf on the north, are often referred to as the "Third Coast" of the United States.