Belleville is a city in St. Clair County, Illinois, United States. The population was 41,410 at the 2000 census. It is the county seat of St. Clair County, and the seat of the Roman Catholic Diocese of Belleville and the National Shrine of Our Lady of the Snows. Belleville is also the home of the newspaper, the Belleville News-Democrat. Belleville is in the Metro-East region of the St. Louis, Missouri metropolitan area. Belleville's sister city is Paderborn, Germany. It is commonly said that Belleville has the longest Main Street in the world, stretching for 13 miles. The first kindergarten in the United States was located in Belleville. Belleville apartments for rent comparison page shows most up to date rent information on Belleville apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.