Marietta is a city in and the county seat of Cobb County, Georgia, United States. At the 2020 census, the city had a population of 60,972. The 2019 estimate was 60,867, making it one of Atlanta's largest suburbs. Marietta is the fourth largest of the principal cities by population of the Atlanta metropolitan area.

Cobb County is a county in the U.S. state of Georgia, located in the Atlanta metropolitan area in the north central portion of the state. As of 2020 Census, the population was 766,149. It is the state's third most populous county, after Fulton and Gwinnett counties. Its county seat is Marietta; its largest city is Mableton.