South Ben is a city on the St. Joseph river and a twin city of Mishawaka in St. Joseph County, Indiana, United States. As of the 2000 census, the city had a total of 107,789 residents; its metropolitan area had a population of 316,663. It is the fourth largest city in Indiana and county seat of St. Joseph County. It is the economic and cultural hub of the region commonly known as Michiana, and may be best known as the home of the University of Notre Dame.