Lake City is located in northern Clayton County at 33°36′29″N 84°20′26″W / 33.60806°N 84.34056°W / 33.60806; -84.34056 (33.608109, -84.340481). It is bordered to the south by Morrow and to the west and north by Forest Park. Fort Gillem is directly to the north, within the Forest Park city limits. Downtown Atlanta is 11 miles (18 km) to the north.
As of the census of 2000, there were 2,886 people, 950 households, and 690 families residing in the city. The population density was 1,594.5 people per square mile (615.6/km2). There were 1,022 housing units at an average density of 564.6 per square mile (218.0/km2). The racial makeup of the city was 51.91% White, 32.22% African American, 0.94% Native American, 9.67% Asian, 0.14% Pacific Islander, 3.19% from other races, and 1.94% from two or more races. Hispanic or Latino people of any race were 7.48% of the population.