Hattiesburg is the 5th most populous city in the U.S. state of Mississippi, located primarily in Forrest County and extending west into Lamar County. The city population was 45,989 at the 2010 census, with the population now being 48,730 in 2020. Hattiesburg is the principal city of the Hattiesburg Metropolitan Statistical Area, which encompasses Covington, Forrest, Lamar, and Perry counties. The city is located in the Pine Belt region.

Mississippi is a state in the Southeastern region of the United States. It borders Tennessee to the north, Alabama to the east, the Gulf of Mexico to the south, Louisiana to the southwest, and Arkansas to the northwest. Mississippi's western boundary is largely defined by the Mississippi River, or its historical course. Mississippi is the 32nd largest by area and 35th-most populous of the 50 U.S. states and has the lowest per-capita income. Jackson is both the state's capital and largest city. Greater Jackson is the state's most populous metropolitan area, with a population of 591,978 in 2020.