Chatham County is the most populous county in the Coastal Georgia region and the most populous county in the State of Georgia outside the Atlanta metropolitan area, with an estimated 2016 population of 289,082 people, according to the 2016 American Community Survey. One of the original counties of Georgia, Chatham County was created February 5, 1777, and is named after William Pitt, 1st Earl of Chatham.

 It is home to seven incorporated municipal governments, the principal of which is the City of Savannah, which makes up for more than half the county's residents and serves as the county seat.
 

 

Chatham County Population Trends

1790 10,769  
1800 12,946   20.2%
1810 13,540   4.6%
1820 14,737   8.8%
1830 14,127   −4.1%
1840 18,801   33.1%
1850 23,901   27.1%
1860 31,043   29.9%
1870 41,279   33.0%
1880 45,023   9.1%
1890 57,740   28.2%
1900 71,239   23.4%
1910 79,690   11.9%
1920 100,032   25.5%
1930 105,431   5.4%
1940 117,970   11.9%
1950 151,481   28.4%
1960 188,299   24.3%
1970 187,767   −0.3%
1980 202,226   7.7%
1990 216,935   7.3%
2000 232,048   7.0%
2010 265,128   14.3%
2016 289,053   9.6%