Thomson is a city and the county seat of McDuffie County, Georgia, United States. The population was 6,814 at the 2020 census. Thomson's nickname is "The Camellia City of the South", in honor of the thousands of camellia plants throughout the city. Thomson was founded in 1837 as a depot on the Georgia Railroad. It was renamed in 1853 for railroad official John Edgar Thomson and incorporated February 15, 1854 as a town and in 1870 as a city.