Oglethorpe County is a county located in the northeastern part of the U.S. state of Georgia. As of the 2020 census, the population was 14,825. The county seat is Lexington. Oglethorpe County is included in the Athens-Clarke County, GA Metropolitan Statistical Area, which is also included in the Atlanta-Athens-Clarke County-Sandy Springs, GA Combined Statistical Area. It is the largest county in Northeast Georgia.