Birmingham is a city in the north central region of the U.S. state of Alabama. With an estimated 2018 population of 209,880, it is the most populous city in Alabama. Birmingham is the seat of Jefferson County, Alabama's most populous and fifth largest county. As of 2018, the Birmingham-Hoover Metropolitan Statistical Area had a population of 1,151,801, making it the most populous in Alabama and 49th-most populous in the United States. Birmingham serves as an important regional hub and is associated with the Deep South, Piedmont, and Appalachian regions of the nation.