| Castel Gandolfo to Oswego (Illinois) | 4,859.43 mi (7,820.50 km) |
| Castel Gandolfo to Oswego (New York) | 4,299.61 mi (6,919.55 km) |
| Castel Gandolfo to Otsego (Minnesota) | 4,904.38 mi (7,892.83 km) |
| Castel Gandolfo to Ottawa (Illinois) | 4,893.35 mi (7,875.09 km) |
| Castel Gandolfo to Ottawa (Kansas) | 5,275.09 mi (8,489.44 km) |
| Castel Gandolfo to Ottumwa (Iowa) | 5,050.98 mi (8,128.77 km) |
| Castel Gandolfo to Overland (Missouri) | 5,073.94 mi (8,165.71 km) |
| Castel Gandolfo to Overland Park (Kansas) | 5,238.81 mi (8,431.06 km) |
| Castel Gandolfo to Overlea (Maryland) | 4,455.82 mi (7,170.95 km) |
| Castel Gandolfo to Oviedo (Florida) | 5,113.51 mi (8,229.41 km) |
| Castel Gandolfo to Owasso (Oklahoma) | 5,407.46 mi (8,702.46 km) |
| Castel Gandolfo to Owatonna (Minnesota) | 4,942.95 mi (7,954.90 km) |
| Castel Gandolfo to Owensboro (Kentucky) | 4,980.53 mi (8,015.39 km) |
| Castel Gandolfo to Owings Mills (Maryland) | 4,466.06 mi (7,187.43 km) |
| Castel Gandolfo to Owosso (Michigan) | 4,635.89 mi (7,460.74 km) |
