Cobb, along with several adjoining counties, was created on December 3, 1832, by the Georgia General Assembly from the huge Cherokee "county" territoryland northwest of the Chattahoochee River which the state confiscated from the Cherokee Nation and redistributed to settlers via lottery, following the passage of the federal Indian Removal Act. The county was named for Thomas Willis Cobb, a United States representative and senator from Georgia. It is believed Marietta was named for his wife, Mary.
Cobb County is included in the Atlanta-Sandy Springs-Roswell, GA Metropolitan Statistical Area. It is situated immediately to the northwest of Atlanta's city limits.
Its Cumberland District, an edge city, has over 24,000,000 square feet (2,200,000 m2) of office space. As of 2017, Major League Baseball's Atlanta Braves play in Cumberland.
The U.S. Census Bureau ranks Cobb County as the most-educated in the state of Georgia and 12th among all counties in the United States. It has ranked among the top 100 wealthiest counties in the United States.
Cobb County maintains the Cobb County Public Library System. The libraries provide resources such as books, videos, internet access, printing, and computer classes. The libraries in the CCPLS are:
The Smyrna Public Library is a city-owned library in Smyrna.
Under Georgia's home rule provision, county governments have free rein to legislate on all matters within the county, provided that such legislation does not conflict with state or federal laws or constitutions.
Cobb County is governed by a five-member board of commissioners, which has both legislative and executive authority within the county. The chairman of the board is elected county-wide. The other four commissioners are elected from single-member districts. The board hires a county manager who oversees day-to-day operations of the county's executive departments.
County residents also elect a sheriff, district attorney, probate court judge, clerk of superior court, clerk of the state court, state court solicitor, chief magistrate judge (who then appoints other magistrate court judges), superior court judges, state court judges, tax commissioner, surveyor, and a seven-member board of education. In addition to the county sheriff, the constitutional chief law enforcement officer of the county, Cobb County has a separate police department under the authority of the Board of Commissioners. The sheriff oversees the jail, to which everyone arrested under state law is taken, regardless of the city or other area of the county where it happens, or what police department makes the arrest.
Each city has a separate police department, answerable to its governing council. Marietta, Smyrna, and Austell have separate fire departments, with the Cobb County Fire Department being the authority having jurisdiction over Kennesaw, Acworth, Powder Springs, and unincorporated areas. Cobb 911 covers unincorporated areas and the cities of Marietta and Powder Springs. Kennesaw and Acworth jointly operate a small 911 call center (PSAP) upstairs in Kennesaw city hall, dispatching the police departments in both cities, and forwarding fire calls to Cobb. Austell and Smyrna operate their own separate 911 systems.
The county retails potable water to much of the county, and wholesales it to various cities.
The current County Manager is David Hankerson.
Cobb County like many suburban counties across the nation has traditionally voted Republican and even voted for Ronald Reagan over Georgia native son Jimmy Carter in his reelection bid. Before 2016 election, it had not voted for a Democrat since native son Jimmy Carter ran in 1976. In the 2000s and 2010s many minorities and northerners have moved to Cobb making it more competitive. In 2016 Hillary Clinton won Cobb along with nearby Gwinnett county, with a vote proportion matching closely that of the rest of the nation (48%). It shares this trend with other traditionally Republican suburban stronghold that flipped in 2016 such as Fort Bend County and Orange County signifying a major shift in political leaning in metropolitan areas across the Sun Belt.