Ellenwood is an unincorporated community in Clayton, Henry, Rockdale and DeKalb counties in the U.S. state of Georgia. The community is a southeast suburb of Atlanta and is located along Interstate 675 and Georgia State Route 42. With a population of 46,967 and ten constituent neighborhoods, Ellenwood is the 19th largest community in Georgia. Ellenwood has a post office with ZIP code 30294.