Shelby County is a county of the U.S. state of Alabama and is named in honor of Isaac Shelby, Governor of Kentucky. The county seat of Shelby County is Columbiana. As of 2009 U.S. Census estimated the population was 192,503. Shelby County ranks among the 100 highest-income counties in the United States. Shelby County's growth has accompanied the decline of Birmingham and Jefferson County.

The county's newspaper is the Shelby County Reporter. Shelby County was established on February 7, 1818, and named for Governor Isaac Shelby (1750–1826), of Kentucky.According to the U.S. Census Bureau, the county has a total area of 810 square miles (2,097 km²), of which 795 square miles (2,058 km²) is land and 15 square miles (38 km²) (1.83%) is water