Greenacres is a city in Palm Beach County, Florida, United States. It is part of South Florida's Miami metropolitan area. As of the 2020 census, the city had a population of 43,990 residents. Frederick E. Bryant, Harold J. Bryant, and William Greenwood of the Palm Beach Farms Company began buying and selling thousands of acres of land in the area by 1909. However, difficulties with farming in wetland conditions left the land mostly unused until the 1920s land boom. Lawrence Carter "L. C." Swain then platted the original section of Greenacres beginning in 1923.