Poplar Bluff is a small city in Butler County in Southeast Missouri in the United States. It is the county seat of Butler County and is known as "The Gateway to the Ozarks" and "Little Chicago" among other names. The population was 17,023 at the 2010 census.The Poplar Bluff Micropolitan Statistical Area consists of all of Butler County. The city is at the crossroads of U.S. Route 60 and U.S. Route 67.