| Casale Monferrato to Olympia Heights (Florida) | 4,924.86 mi (7,925.80 km) |
| Casale Monferrato to Omaha (Nebraska) | 4,867.90 mi (7,834.12 km) |
| Casale Monferrato to On Top of the World Designated Place (Florida) | 4,858.73 mi (7,819.37 km) |
| Casale Monferrato to Onalaska (Wisconsin) | 4,563.40 mi (7,344.08 km) |
| Casale Monferrato to Oneida (New York) | 3,974.96 mi (6,397.08 km) |
| Casale Monferrato to Oneonta (New York) | 3,973.72 mi (6,395.08 km) |
| Casale Monferrato to Ontario (California) | 6,010.07 mi (9,672.27 km) |
| Casale Monferrato to Ontario (Oregon) | 5,427.34 mi (8,734.46 km) |
| Casale Monferrato to Opa-locka (Florida) | 4,912.88 mi (7,906.52 km) |
| Casale Monferrato to Opelika (Alabama) | 4,833.36 mi (7,778.54 km) |
| Casale Monferrato to Opelousas (Louisiana) | 5,222.86 mi (8,405.38 km) |
| Casale Monferrato to Orange (California) | 6,030.48 mi (9,705.12 km) |
| Casale Monferrato to Orange (Texas) | 5,313.69 mi (8,551.56 km) |
| Casale Monferrato to Orange City (Florida) | 4,821.27 mi (7,759.08 km) |
| Casale Monferrato to Orangeburg (South Carolina) | 4,597.75 mi (7,399.36 km) |
