| Castelnuovo Rangone to Olympia Heights (Florida) | 5,052.64 mi (8,131.44 km) |
| Castelnuovo Rangone to Omaha (Nebraska) | 4,986.55 mi (8,025.08 km) |
| Castelnuovo Rangone to On Top of the World Designated Place (Florida) | 4,986.15 mi (8,024.44 km) |
| Castelnuovo Rangone to Onalaska (Wisconsin) | 4,682.46 mi (7,535.69 km) |
| Castelnuovo Rangone to Oneida (New York) | 4,099.53 mi (6,597.56 km) |
| Castelnuovo Rangone to Oneonta (New York) | 4,098.72 mi (6,596.25 km) |
| Castelnuovo Rangone to Ontario (California) | 6,120.38 mi (9,849.81 km) |
| Castelnuovo Rangone to Ontario (Oregon) | 5,531.18 mi (8,901.57 km) |
| Castelnuovo Rangone to Opa-locka (Florida) | 5,040.67 mi (8,112.17 km) |
| Castelnuovo Rangone to Opelika (Alabama) | 4,959.57 mi (7,981.66 km) |
| Castelnuovo Rangone to Opelousas (Louisiana) | 5,348.10 mi (8,606.94 km) |
| Castelnuovo Rangone to Orange (California) | 6,140.78 mi (9,882.62 km) |
| Castelnuovo Rangone to Orange (Texas) | 5,438.59 mi (8,752.57 km) |
| Castelnuovo Rangone to Orange City (Florida) | 4,948.80 mi (7,964.33 km) |
| Castelnuovo Rangone to Orangeburg (South Carolina) | 4,724.57 mi (7,603.46 km) |
