Hialeah is a city in Miami-Dade County, Florida, United States. With a population of 223,109 as of the 2020 census, Hialeah is the sixth-largest city in Florida. It is the second largest city by population in the Miami metropolitan area of South Florida, which was home to an estimated 6,198,782 people at the 2018 census. It is located west-northwest of Miami, and is one of a few places in the county—others being Homestead, Miami Beach, Surfside, Bal Harbour, Sunny Isles Beach, and Golden Beach—to have its own street grid numbered separately from the rest of the county (which is otherwise based on Miami Avenue at Flagler Street in Downtown Miami, the county seat).