Miami is a major city in southeastern Florida, in the United States. It is the county seat of Miami-Dade County. Miami is a gamma world city with an estimated population of 404,048. It is the largest city within the South Florida metropolitan area, which is the largest metropolitan area in the Southeastern United States with.4 million people. Miami and its surrounding cities make up the fifth largest urban area in the United States. Miami apartments for rent comparison page shows most up to date rent information on Miami apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.