Cobb County is a suburban county in the state of Georgia. As of the 2015, the population was 741,334, making it Georgia’s third-most populous county. Its county seat and largest city is Marietta.

Cobb County was one of the 24 created in 1832 from Cherokee Indian territory. It is named for Judge Thomas W. Cobb, a former U.S. senator. Marietta, the county seat, is named for his wife. In frontier days, the Chattahoochee River, which forms Cobb’s southeast boundary, served as a dividing line between Creek and Cherokee Indian territories.