Castalian Springs is an unincorporated community and census-designated place (CDP) in Sumner County, Tennessee, United States.

The Native Americans who built and occupied the complex site preceded the historic tribes later known to European-American settlers in the area.

It was excavated professionally in the 2005 to 2010 archaeological field school led by Dr. Kevin E. Smith from Middle Tennessee State University.

A number of important finds have been associated with the site, most particularly several examples of Mississippian stone statuary and the "Castalian Springs shell gorget," now held by the National Museum of the American Indian.

[6] Castalian Springs captured national news headlines when an 11-month-old boy, Kyson Stowell, was found alive in the debris of his house.