Huntsville is the most populous city in the U.S. state of Alabama. The population was 215,006 at the 2020 census, and was estimated to b…Huntsville is the most populous city in the U.S. state of Alabama. The population was 215,006 at the 2020 census, and was estimated to be 221,933 in 2022, making it the 100th-most populous in the U.S. The Huntsville metropolitan area's population was estimated at 527,000 in 2023 and is the second-most populous metro area in the state after Birmingham. Huntsville is the seat of Madison County, with portions extending into Limestone County and Morgan County.