Calera is a city in Shelby and Chilton counties in the U.S. state of Alabama. It is the location of the Shelby County Airport. Calera's population was 3,158 at the 2000 census.As of the 2010 census the population had more than tripled to 11,620, making it the fastest-growing city in Alabama. It is within the Birmingham-Hoover, Alabama Metropolitan Statistical Area and positively affected by the growth in its economy.