| Castrovillari to Olympia Heights (Florida) | 5,424.79 mi (8,730.36 km) |
| Castrovillari to Omaha (Nebraska) | 5,406.48 mi (8,700.89 km) |
| Castrovillari to On Top of the World Designated Place (Florida) | 5,370.97 mi (8,643.74 km) |
| Castrovillari to Onalaska (Wisconsin) | 5,101.90 mi (8,210.72 km) |
| Castrovillari to Oneida (New York) | 4,506.41 mi (7,252.36 km) |
| Castrovillari to Oneonta (New York) | 4,503.77 mi (7,248.13 km) |
| Castrovillari to Ontario (California) | 6,544.00 mi (10,531.56 km) |
| Castrovillari to Ontario (Oregon) | 5,952.46 mi (9,579.55 km) |
| Castrovillari to Opa-locka (Florida) | 5,413.12 mi (8,711.58 km) |
| Castrovillari to Opelika (Alabama) | 5,357.33 mi (8,621.79 km) |
| Castrovillari to Opelousas (Louisiana) | 5,751.42 mi (9,256.02 km) |
| Castrovillari to Orange (California) | 6,564.39 mi (10,564.37 km) |
| Castrovillari to Orange (Texas) | 5,843.52 mi (9,404.24 km) |
| Castrovillari to Orange City (Florida) | 5,331.36 mi (8,580.00 km) |
| Castrovillari to Orangeburg (South Carolina) | 5,117.39 mi (8,235.65 km) |
