Hialeah is a city in Miami-Dade County, Florida, United States. With a population of 223,109 as of the 2020 census, it is the sixth-largest city in Florida. It is the second largest city by population in Miami-Dade County, 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 p…