Jasper is a city in Dubois County, Indiana, United States located along the Patoka River. The population was 15,038 at the 2010 census making it the 55th largest city in Indiana. Jasper has been the county seat of Dubois County since 1830, succeeding Portersville. On November 4, 2007, Dubois County returned to the Eastern Time Zone, after having moved to the Central Time Zone the previous year. The land uses are mainly agriculture.