Cornersville is a town in Marshall County, Tennessee, United States. The population was 962 at the 2000 census.
Before becoming incorporated the town's name was Marathon because the distance to Pulaski was equal to a marathon. When it was first incorporated as a municipality on January 7, 1830, Cornersville was named for its location near the corner where Giles, Maury, Bedford and Lincoln counties came together. It was part of Giles County at the time of incorporation, but county boundaries have changed, and since 1870 it has been in Marshall County.
Cornersville is located at 35°21′29″N 86°50′30″W / 35.35806°N 86.84167°W / 35.35806; -86.84167 (35.358152, -86.841681).