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. Both the city and the Florence-Muscle Shoals Metropolitan Area are commonly called "The Shoals". Northwest Alabama Regional Airport serves the Shoals region, located in the northwest section of the state in Muscle Shoals.