Calhoun County is located in the panhandle of Florida. Calhoun County contains some 567 square miles of land and 7 square miles of water surface. The county seat is Blountstown.

When it was created in 1838, Calhoun County was named for John C. Calhoun (Senator from South Carolina and US Vice President under John Quincy Adams and Andrew Jackson).

Calhoun County is the site of "Look and Tremble," a Class I rapids on the Chipola River. Because of the generally flat landscape, rapids of any sort on a Florida river are unusual. As the underlying rock in the area is "swiss-cheese-like" limestone, among the holes in the river bottom folks have found animal fossils and Native American artifacts that have washed downstream.