Muscle Shoals is the largest city in Colbert County, Alabama, United States. It is located on the left bank of the Tennessee River in the northern part of the state and, as of the 2010 census, its population was 13,146. The estimated population in 2019 was 14,575.

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.