Pemiscot County is a county located in the southeastern corner in the Bootheel in the U.S. state of Missouri. As of the 2010 census, the population was 18,296. The largest city and county seat is Caruthersville. The county was officially organized on February 19, 1851, and is named for the local bayou, taken from the Fox dialect word, pem-eskaw, meaning "liquid mud". Bordering the Mississippi River and floodplain, the county has been devoted to agricultural development and commodity crops. With mechanization of agriculture, its population has declined since a peak in 1940.