Cottontown is an unincorporated community and census-designated place (CDP) in Sumner County, Tennessee, United States. 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.Notable MentionsKing Homestead Historic homeplace is located in Cottontown just off of Hwy 25.