Grantville is located along the southern border of Coweta County at 33°14′14″N 84°49′37″W / 33.23722°N 84.82694°W / 33.23722; -84.82694 (33.237252, -84.827059). U.S. Route 29 runs through the city, passing south of the center, while Interstate 85 passes through the eastern part of the city, crossing US 29 at Exit 35. I-85 leads northeast 46 miles (74 km) to Atlanta and southwest 114 miles (183 km) to Montgomery, Alabama, while US 29, a more local road, leads north 12 miles (19 km) to Newnan, the Coweta County seat, and southwest 20 miles (32 km) to LaGrange.
As of the census of 2000, there were 1,309 people, 516 households, and 359 families residing in the city. The population density was 252.0 people per square mile (97.4/km2). There were 569 housing units at an average density of 109.6 per square mile (42.3/km2). The racial makeup of the city was 69.29% White, 28.50% African American, 0.31% Native American, 0.53% Asian, 1.15% from other races, and 0.23% from two or more races. Hispanic or Latino of any race were 1.45% of the population.