Peachtree Corners is a city in Gwinnett County, Georgia, United States. It is part of the Atlanta metropolitan area, and is the largest city in Gwinnett County with a population of 42,243 as of the 2020 U.S. census. Peachtree Corners is the only Atlanta northern suburb developed as a planned community. The city is bordered to the north and west by the Chattahoochee River and is located east of Dunwoody.