| Altadena to Olympia Heights (Florida) | 2,322.70 mi (3,738.03 km) |
| Altadena to Omaha (Nebraska) | 1,297.23 mi (2,087.69 km) |
| Altadena to On Top of the World Designated Place (Florida) | 2,126.51 mi (3,422.28 km) |
| Altadena to Onalaska (Wisconsin) | 1,583.24 mi (2,547.98 km) |
| Altadena to Oneida (New York) | 2,346.13 mi (3,775.74 km) |
| Altadena to Oneonta (New York) | 2,376.36 mi (3,824.39 km) |
| Altadena to Ontario (California) | 32.02 mi (51.53 km) |
| Altadena to Ontario (Oregon) | 682.22 mi (1,097.93 km) |
| Altadena to Opa-locka (Florida) | 2,322.62 mi (3,737.89 km) |
| Altadena to Opelika (Alabama) | 1,883.82 mi (3,031.72 km) |
| Altadena to Opelousas (Louisiana) | 1,537.20 mi (2,473.89 km) |
| Altadena to Orange (California) | 32.30 mi (51.98 km) |
| Altadena to Orange (Texas) | 1,449.51 mi (2,332.77 km) |
| Altadena to Orange City (Florida) | 2,187.40 mi (3,520.29 km) |
| Altadena to Orangeburg (South Carolina) | 2,127.16 mi (3,423.33 km) |
