Shelby County is the westernmost county in the U.S. state of Tennessee. As of the 2020 census, the population was 929,744. It is the largest of the state's 95 counties, both in terms of population and geographic area. Its county seat is Memphis, a port on the Mississippi River and the second most populous city in the state. The county was named for Governor …Shelby County is the westernmost county in the U.S. state of Tennessee. As of the 2020 census, the population was 929,744. It is the largest of the state's 95 counties, both in terms of population and geographic area. Its county seat is Memphis, a port on the Mississippi River and the second most populous city in the state. The county was named for Governor Isaac Shelby of Kentucky. It is one of only two remaining counties in Tennessee with a majority African American population, along with Haywood County. Shelby County is part of the Memphis, TN–MS–AR Metropolitan Statistical Area. It is bordered on the west by the Mississippi River. Located within the Mississippi Delta, the county was developed as a center of cotton plantations in the antebellum era, and cotton continued as an important commodity crop well into the 20th century. The economy has become more diversified.