| Guardiagrele to Olympia Heights (Florida) | 5,264.87 mi (8,472.98 km) |
| Guardiagrele to Omaha (Nebraska) | 5,217.72 mi (8,397.12 km) |
| Guardiagrele to On Top of the World Designated Place (Florida) | 5,204.06 mi (8,375.12 km) |
| Guardiagrele to Onalaska (Wisconsin) | 4,913.54 mi (7,907.57 km) |
| Guardiagrele to Oneida (New York) | 4,326.51 mi (6,962.85 km) |
| Guardiagrele to Oneonta (New York) | 4,324.99 mi (6,960.40 km) |
| Guardiagrele to Ontario (California) | 6,350.43 mi (10,220.03 km) |
| Guardiagrele to Ontario (Oregon) | 5,758.03 mi (9,266.65 km) |
| Guardiagrele to Opa-locka (Florida) | 5,253.03 mi (8,453.93 km) |
| Guardiagrele to Opelika (Alabama) | 5,183.03 mi (8,341.27 km) |
| Guardiagrele to Opelousas (Louisiana) | 5,573.86 mi (8,970.27 km) |
| Guardiagrele to Orange (California) | 6,370.81 mi (10,252.83 km) |
| Guardiagrele to Orange (Texas) | 5,664.99 mi (9,116.92 km) |
| Guardiagrele to Orange City (Florida) | 5,165.70 mi (8,313.39 km) |
| Guardiagrele to Orangeburg (South Carolina) | 4,945.90 mi (7,959.65 km) |
