| Marietta to Olympia Heights (Florida) | 621.72 mi (1,000.56 km) |
| Marietta to Omaha (Nebraska) | 806.24 mi (1,297.52 km) |
| Marietta to On Top of the World Designated Place (Florida) | 360.28 mi (579.81 km) |
| Marietta to Onalaska (Wisconsin) | 773.67 mi (1,245.11 km) |
| Marietta to Oneida (New York) | 791.36 mi (1,273.57 km) |
| Marietta to Oneonta (New York) | 779.82 mi (1,255.00 km) |
| Marietta to Ontario (California) | 1,885.64 mi (3,034.65 km) |
| Marietta to Ontario (Oregon) | 1,860.76 mi (2,994.61 km) |
| Marietta to Opa-locka (Florida) | 612.63 mi (985.93 km) |
| Marietta to Opelika (Alabama) | 101.45 mi (163.28 km) |
| Marietta to Opelousas (Louisiana) | 500.03 mi (804.72 km) |
| Marietta to Orange (California) | 1,900.51 mi (3,058.58 km) |
| Marietta to Orange (Texas) | 600.97 mi (967.17 km) |
| Marietta to Orange City (Florida) | 396.20 mi (637.62 km) |
| Marietta to Orangeburg (South Carolina) | 213.57 mi (343.70 km) |
