| Opfikon to Olympia Heights (Florida) | 4,881.58 mi (7,856.15 km) |
| Opfikon to Omaha (Nebraska) | 4,771.61 mi (7,679.17 km) |
| Opfikon to On Top of the World Designated Place (Florida) | 4,805.21 mi (7,733.23 km) |
| Opfikon to Onalaska (Wisconsin) | 4,468.34 mi (7,191.11 km) |
| Opfikon to Oneida (New York) | 3,900.19 mi (6,276.74 km) |
| Opfikon to Oneonta (New York) | 3,901.17 mi (6,278.33 km) |
| Opfikon to Ontario (California) | 5,895.75 mi (9,488.29 km) |
| Opfikon to Ontario (Oregon) | 5,303.28 mi (8,534.81 km) |
| Opfikon to Opa-locka (Florida) | 4,869.39 mi (7,836.52 km) |
| Opfikon to Opelika (Alabama) | 4,767.74 mi (7,672.94 km) |
| Opfikon to Opelousas (Louisiana) | 5,150.87 mi (8,289.53 km) |
| Opfikon to Orange (California) | 5,916.12 mi (9,521.08 km) |
| Opfikon to Orange (Texas) | 5,239.78 mi (8,432.62 km) |
| Opfikon to Orange City (Florida) | 4,769.74 mi (7,676.16 km) |
| Opfikon to Orangeburg (South Carolina) | 4,537.35 mi (7,302.16 km) |
