| Hamm to Olympia Heights (Florida) | 4,766.79 mi (7,671.40 km) |
| Hamm to Omaha (Nebraska) | 4,564.51 mi (7,345.88 km) |
| Hamm to On Top of the World Designated Place (Florida) | 4,672.42 mi (7,519.54 km) |
| Hamm to Onalaska (Wisconsin) | 4,264.18 mi (6,862.54 km) |
| Hamm to Oneida (New York) | 3,733.43 mi (6,008.38 km) |
| Hamm to Oneonta (New York) | 3,738.37 mi (6,016.33 km) |
| Hamm to Ontario (California) | 5,656.75 mi (9,103.66 km) |
| Hamm to Ontario (Oregon) | 5,049.89 mi (8,127.01 km) |
| Hamm to Opa-locka (Florida) | 4,754.25 mi (7,651.23 km) |
| Hamm to Opelika (Alabama) | 4,613.70 mi (7,425.03 km) |
| Hamm to Opelousas (Louisiana) | 4,984.35 mi (8,021.54 km) |
| Hamm to Orange (California) | 5,677.04 mi (9,136.32 km) |
| Hamm to Orange (Texas) | 5,069.65 mi (8,158.81 km) |
| Hamm to Orange City (Florida) | 4,640.66 mi (7,468.43 km) |
| Hamm to Orangeburg (South Carolina) | 4,393.42 mi (7,070.53 km) |
