Jacksonville is a city in Calhoun County, Alabama, United States. As of the 2020 census the population was 14,385, which is a 14.6% increase s…Jacksonville is a city in Calhoun County, Alabama, United States. As of the 2020 census the population was 14,385, which is a 14.6% increase since 2010 and a 71.2% increase since 2000. It is included in the Anniston-Oxford Metropolitan Statistical Area. The city is home to Jacksonville State University, which is a center of commerce and one of the largest employers in the area.