| Oceanside to Olympia Heights (Florida) | 2,270.90 mi (3,654.66 km) |
| Oceanside to Omaha (Nebraska) | 1,289.70 mi (2,075.58 km) |
| Oceanside to On Top of the World Designated Place (Florida) | 2,080.29 mi (3,347.90 km) |
| Oceanside to Onalaska (Wisconsin) | 1,581.58 mi (2,545.31 km) |
| Oceanside to Oneida (New York) | 2,336.51 mi (3,760.24 km) |
| Oceanside to Oneonta (New York) | 2,365.14 mi (3,806.33 km) |
| Oceanside to Ontario (California) | 58.84 mi (94.69 km) |
| Oceanside to Ontario (Oregon) | 746.50 mi (1,201.38 km) |
| Oceanside to Opa-locka (Florida) | 2,271.20 mi (3,655.14 km) |
| Oceanside to Opelika (Alabama) | 1,844.67 mi (2,968.71 km) |
| Oceanside to Opelousas (Louisiana) | 1,488.22 mi (2,395.05 km) |
| Oceanside to Orange (California) | 49.76 mi (80.08 km) |
| Oceanside to Orange (Texas) | 1,398.09 mi (2,250.01 km) |
| Oceanside to Orange City (Florida) | 2,141.43 mi (3,446.30 km) |
| Oceanside to Orangeburg (South Carolina) | 2,092.08 mi (3,366.88 km) |
