Peachtree Corners is a city in western Gwinnett County, Georgia, United States. It is a northern suburb of Atlanta, and is the largest city in Gwinnett County, with an estimated population of 42,773 in 2016. The city, bordered to the north and west by the Chattahoochee River, is located east of Dunwoody and south of Johns Creek. Peachtree Corners is the only one of Atlanta's northern suburbs that was developed as a planned community.