Hales Bar Dam was a hydroelectric dam once located on the Tennessee River in Marion County, Tennessee, United States. The Chattanooga and Tennessee River Power Company began building the dam on October 17, 1905, and completed it on November 11, 1913, making Hales Bar one of the first major multipurpose dams and one of the first major dams to be built across a navigable channel in the United States. It began operation on November 13, 1913.