Upson County is a county located in the west central portion of the U.S. state of Georgia. As of the 2010 census, the population was 27,153. The county seat is Thomaston. The county was created on December 15, 1824. Upson County comprises the Thomaston, GA Micropolitan Statistical Area, which is also included in the Atlanta-Athens-Clarke County-Sandy Springs, GA Combined Statistical Area. The vast majority of Upson County is located in the Upper Flint River sub-basin of the ACF River Basin (Apalachicola-Chattahoochee-Flint River Basin), with just a tiny northeastern corner of the county, north of Yatesville, located in the Upper Ocmulgee River sub-basin of the Altamaha River basin. As of the 2010 United States Census, there were 27,153 people, 10,716 households, and 7,382 families residing in the county.