Locust Grove is a city in Henry County, Georgia, United States. The population was 5,402 at the 2010 census. It is one of Atlanta's most Southeastern Suburbs in the Metropolitan area. Some unincorporated communities such as Luella and many rural areas surround Locust Grove and addresses in those communities have Locust Grove postal addresses.Locust Grove has experienced a growth in population and in businesses coming into the area.