Southern Indiana is a geographic and cultural region that generally comprises the southern third of the U.S. state of Indiana and borders the states of Illinois to the west, Kentucky to the south, and Ohio to the east. Spanning the state's southernmost 33 counties, its main population centers include Southwestern Indiana, the Louisville metropolitan are…Southern Indiana is a geographic and cultural region that generally comprises the southern third of the U.S. state of Indiana and borders the states of Illinois to the west, Kentucky to the south, and Ohio to the east. Spanning the state's southernmost 33 counties, its main population centers include Southwestern Indiana, the Louisville metropolitan area (south), and the Cincinnati metropolitan area. The region's history and geography have led to a blending of Southern and Midwestern cultures, distinct from the rest of the state. It is often considered to be part of the Upland South and the Southern influenced Lower Midwest.