Poplar Bluff is a city in Butler County located in Southeast Missouri in the United States. It is the county seat of Butler County and is known as "The Gateway to the Ozarks" among other names. The population was 17,023 at the 2010 census. It is the second largest city in Missouri's 8th Congressional District after Cape Girardeau. The Poplar Bluff Micropolitan Statistical Area consists of all of Butler County. The city is at the crossroads of U.S. Highway 60 and U.S. Highway 67.