16 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Mableton | 1 | 78,614 | 41,647 | 85.4% | 3,850 | 20 | CDP |
| Mableton | 2 | 78,614 | 41,647 | 0.38% | 3,850 | 20 | CDP |
| Mableton | 3 | 78,614 | 77,114 | 85.4% | 3,850 | 20 | CDP |
| Mableton | 4 | 78,614 | 77,114 | 0.38% | 3,850 | 20 | CDP |
| Marietta | 5 | 63,643 | 61,036 | 0.83% | 2,707 | 24 | City |
| Smyrna | 6 | 57,429 | 56,167 | 0.44% | 3,591 | 16 | City |
| Mableton | 7 | 42,780 | 41,647 | 0.89% | 2,095 | 20 | CDP |
| Mableton | 8 | 42,780 | 41,647 | -45.37% | 2,095 | 20 | CDP |
| Mableton | 9 | 42,780 | 77,114 | 0.89% | 2,095 | 20 | CDP |
| Mableton | 10 | 42,780 | 77,114 | -45.37% | 2,095 | 20 | CDP |
| Kennesaw | 11 | 38,832 | 33,371 | 2.89% | 3,980 | 10 | City |
| Powder Springs | 12 | 20,311 | 16,914 | 3.46% | 2,601 | 8 | City |
| Vinings | 13 | 13,750 | 12,546 | 1.99% | 4,399 | 3 | CDP |
| Fair Oaks | 14 | 9,961 | 9,447 | 1.17% | 5,103 | 2 | CDP |
| Austell | 15 | 8,345 | 7,840 | 1.23% | 1,316 | 6 | City |
| Kennesaw State University | 16 | 3,302 | 3,568 | 7.14% | 8,423 | 0 | CDP |
Mableton is the largest city in Cobb County, with a population of 78,614.
Kennesaw State University is the smallest city in Cobb County, with a population of 3,302.
There are 16 cities in Cobb County, Georgia.