Cottontown is an unincorporated community and census-designated place (CDP) in Sumner County, Tennessee, United States. It was named for Capt. Thomas Cotton, a Revolutionary War veteran from North Carolina. As of the 2010 census, its population was 367. It is located along State Route 25 northwest of neighboring Gallatin. The area has its own Post Office. The United States Postal Service ZIP code for the Cottontown area is 37048.