Lithonia is a city in eastern DeKalb County, Georgia, United States. The city's population was 1,924 at the 2010 census. Lithonia is in the Atlanta metropolitan area.
"Lithonia" means "city/town of stone". Lithonia is in the heart of the Georgian granite-quarrying and viewing region, hence the name of the town, from the Greek λίθος lithos, for stone. The huge nearby granite dome, Stone Mountain, is composed of a rock called granite, while the Lithonia gneiss, is a form of metamorphic rock. The Stone Mountain Granite is younger than, and has intruded the Lithonia Gneiss. The area has a history of rock quarries. The mines were served by the Georgia Railroad and Atlanta, Stone Mountain & Lithonia Railway. Some of the rock quarries have been converted to parkland and the rail lines to rail-trail.