
Union County
- State:
- Tennessee
- County Seat:
- Maynardville
Union County's estimated 2025 population is 21,277 with a growth rate of 1.28% in the past year according to the most recent United States census data. Union County is the 66th largest county in Tennessee. The 2010 population was 19,118 and has seen a growth of 11.29% since that time.