Colbert County is a county located in the northwestern part of the U.S. state of Alabama. As of the 2020 census the county's population was 57,227. The county seat is Tuscumbia. The largest city is Muscle Shoals. The county is named in honor of brothers George and Levi Colbert, who were Chickasaw chiefs in the early 19th century in this territory. Ultimately the federal government forced the removal of most of the Chickasaw and other historic tribes from the Southeast.