what county is southside, tn in?
Southside, Montgomery County, Tennessee. For the community in Hardin County, see Southside, Hardin County, Tennessee. Southside is an unincorporated community in Montgomery County, Tennessee, United States. Southside is located in the southeast corner of the county, 11.5 miles (18.5 km) south-southeast of Clarksville. Southside had a post office until it closed on October 12, 2002; it still has its own ZIP code, 37171.