Tull is a town in Grant County, Arkansas, United States. The population was 448 at the 2010 census, up from 358 in 2000. It is part of the Central Arkansas region. Tull is located in northwestern Grant County and is bordered to the north and northwest by the Saline County line. The northwest border of the town follows the Saline River, a south-flowin…Tull is a town in Grant County, Arkansas, United States. The population was 448 at the 2010 census, up from 358 in 2000. It is part of the Central Arkansas region. Tull is located in northwestern Grant County and is bordered to the north and northwest by the Saline County line. The northwest border of the town follows the Saline River, a south-flowing tributary of the Ouachita River. Tull is 16 miles northwest of Sheridan, the Grant County seat, and 10 miles south of Benton.