Marietta is located in central Cobb County, Georgia, United States, and is the county's seat and largest city.
As of the 2010 census, the city had a total population of 56,579. The 2013 estimate is 59,089, making it one of the Atlanta metropolitan area's largest suburbs. Marietta is the fourth largest of the principal cities (by population) of the Atlanta metropolitan statistical area.
The origin of the name is uncertain. It is believed that the city was named for Mary Cobb, the wife of U.S. Senator and Superior Court judge Thomas Willis Cobb. Judge Cobb is the namesake of the county.
Homes were built by early settlers near the Cherokee town of Big Shanty (now Kennesaw) prior to 1824. The first plat was laid out in 1833. Like most towns, Marietta had a square in the center with a courthouse. The Georgia General Assembly legally recognized the community on December 19, 1834.