LaPorte County is a county located in the U.S. state of Indiana. As of 2020, the population was 112,417. The county seat is the city of La Porte, and the largest city is Michigan City. This county is part of the Northwest Indiana and Michiana regions of the Chicago metropolitan area. The LaPorte County Courthouse is located in the county seat of La Porte …LaPorte County is a county located in the U.S. state of Indiana. As of 2020, the population was 112,417. The county seat is the city of La Porte, and the largest city is Michigan City. This county is part of the Northwest Indiana and Michiana regions of the Chicago metropolitan area. The LaPorte County Courthouse is located in the county seat of La Porte and is listed on the National Register of Historic Places.