Hornersville is a city in Dunklin County, Missouri, United States, founded in 1840. The population was 537 at the 2020 census. Hornersville was …Hornersville is a city in Dunklin County, Missouri, United States, founded in 1840. The population was 537 at the 2020 census. Hornersville was platted in 1842. The city was named for its founder, Dr. William H. Horner, who had settled there in 1832. A post office called Hornersville has been in operation since 1875. Hornersville got train service in 1897 from Paragould, Arkansas when the Paragould Southeastern Railway was completed into town; and, was later linked to Blytheville, Arkansas when that rail line was extended.