Tuscaloosa County is a county in the northwest-central portion of the U.S. state of Alabama and is the center of commerce, education, industry, health care, and entertainment for the region. As of the 2020 census, its population was 227,036, making it the fifth-most populous county in Alabama. The county seat and largest city is Tuscaloosa. Tuscaloosa County is part of the Tuscaloosa, AL Metropolitan Statistical Area, which also includes Hale and Pickens counties.