Knobel is a city in Clay County, Arkansas, United States. The population was 147 at the 2020 census. Knobel was established in the 1870s a…Knobel is a city in Clay County, Arkansas, United States. The population was 147 at the 2020 census. Knobel was established in the 1870s as a stop along the St. Louis, Iron Mountain and Southern Railway. A post office with the name “Knobel” was operating in the town by 1874. In 1884, the railroad constructed a large hotel, Knobel House, and a town was platted shortly afterward. Knobel incorporated in 1896. On January 21, 1999, a violent F4 tornado hit areas around the town.