 As of the 2000 census, the Chillum CDP included Chillum, as well as the adjacent unincorporated communities of Avondale, Carole Highlands, Green Meadows and Lewisdale.Chillum is located at (38.968210, −76.979046).According to the United States Census Bureau, the CDP has a total area of , of which is land and , or 0.94%, is water.