Plainview is a city in Union County, Tennessee, United States. The population was 2,125 at the 2010 census, up from 1,866 at the 2000 census. It is included in the Knoxville, Tennessee Metropolitan Statistical Area. Plainview is located in the southern part of the county, south of Maynardville, the county seat.

Union County is a county located in the U.S. state of Tennessee. As of the 2020 census, its population was 19,802. Its county seat is Maynardville. Union County is included in the Knoxville metropolitan statistical area.