Miami, officially the City of Miami, is a coastal city in the U.S. state of Florida and the county seat of Miami-Dade County in South Florida. It is the core of the Miami metropolitan area, which, with a population of 6.14 million, is the second-largest metropolitan area in the Southeast after Atlanta, and the ninth-largest in the United States. With a population of 442,241 as of the 2020 census, Miami is the second-most populous city in Florida after Jacksonville.