| Sierning to Olympia Heights (Florida) | 5,119.79 mi (8,239.51 km) |
| Sierning to Omaha (Nebraska) | 4,947.33 mi (7,961.96 km) |
| Sierning to On Top of the World Designated Place (Florida) | 5,034.44 mi (8,102.16 km) |
| Sierning to Onalaska (Wisconsin) | 4,646.80 mi (7,478.29 km) |
| Sierning to Oneida (New York) | 4,108.26 mi (6,611.61 km) |
| Sierning to Oneonta (New York) | 4,111.91 mi (6,617.48 km) |
| Sierning to Ontario (California) | 6,035.51 mi (9,713.22 km) |
| Sierning to Ontario (Oregon) | 5,422.65 mi (8,726.92 km) |
| Sierning to Opa-locka (Florida) | 5,107.44 mi (8,219.62 km) |
| Sierning to Opelika (Alabama) | 4,984.65 mi (8,022.02 km) |
| Sierning to Opelousas (Louisiana) | 5,359.74 mi (8,625.67 km) |
| Sierning to Orange (California) | 6,055.77 mi (9,745.82 km) |
| Sierning to Orange (Texas) | 5,446.15 mi (8,764.73 km) |
| Sierning to Orange City (Florida) | 5,000.90 mi (8,048.17 km) |
| Sierning to Orangeburg (South Carolina) | 4,760.22 mi (7,660.83 km) |
