| Castel San Giorgio to Oakley (California) | 6,337.23 mi (10,198.78 km) |
| Castel San Giorgio to Oakton (Virginia) | 4,634.54 mi (7,458.58 km) |
| Castel San Giorgio to Oakville (Missouri) | 5,207.95 mi (8,381.39 km) |
| Castel San Giorgio to Oatfield (Oregon) | 5,922.82 mi (9,531.86 km) |
| Castel San Giorgio to Ocala (Florida) | 5,260.61 mi (8,466.13 km) |
| Castel San Giorgio to Ocean Acres (New Jersey) | 4,467.62 mi (7,189.93 km) |
| Castel San Giorgio to Ocean City (New Jersey) | 4,499.95 mi (7,241.96 km) |
| Castel San Giorgio to Ocean Pines (Maryland) | 4,558.29 mi (7,335.86 km) |
| Castel San Giorgio to Ocean Pointe (Hawaii) | 8,120.89 mi (13,069.30 km) |
| Castel San Giorgio to Ocean Springs (Mississippi) | 5,508.64 mi (8,865.30 km) |
| Castel San Giorgio to Oceanside (California) | 6,479.85 mi (10,428.31 km) |
| Castel San Giorgio to Oceanside (New York) | 4,405.74 mi (7,090.36 km) |
| Castel San Giorgio to Ocoee (Florida) | 5,257.78 mi (8,461.57 km) |
| Castel San Giorgio to Oconomowoc (Wisconsin) | 4,928.45 mi (7,931.57 km) |
| Castel San Giorgio to Odenton (Maryland) | 4,600.71 mi (7,404.13 km) |
