Rosemont is a village in Leyden Township, Cook County, Illinois, United States, located immediately northwest of Chicago. As of the 2020 census, the village had a population of 3,952. The village was incorporated in 1956, though it had been settled long before that. While Rosemont's land area and population are relatively small among municipalities in the Chicago metropolitan area, the village is a major center for commercial activity in the region and is a key component of the Golden Corridor. It contains Allstate Arena, which hosts the Chicago Wolves AHL hockey team. Since its founding, the village has been governed by one family, and has been described as America's "last true political machine".