| Kastamonu to Olympia Heights (Florida) | 6,176.05 mi (9,939.39 km) |
| Kastamonu to Omaha (Nebraska) | 5,922.57 mi (9,531.45 km) |
| Kastamonu to On Top of the World Designated Place (Florida) | 6,085.87 mi (9,794.26 km) |
| Kastamonu to Onalaska (Wisconsin) | 5,629.62 mi (9,060.00 km) |
| Kastamonu to Oneida (New York) | 5,140.04 mi (8,272.09 km) |
| Kastamonu to Oneonta (New York) | 5,146.90 mi (8,283.13 km) |
| Kastamonu to Ontario (California) | 6,918.16 mi (11,133.70 km) |
| Kastamonu to Ontario (Oregon) | 6,263.43 mi (10,080.02 km) |
| Kastamonu to Opa-locka (Florida) | 6,163.64 mi (9,919.42 km) |
| Kastamonu to Opelika (Alabama) | 6,024.43 mi (9,695.38 km) |
| Kastamonu to Opelousas (Louisiana) | 6,388.29 mi (10,280.96 km) |
| Kastamonu to Orange (California) | 6,937.81 mi (11,165.32 km) |
| Kastamonu to Orange (Texas) | 6,470.83 mi (10,413.79 km) |
| Kastamonu to Orange City (Florida) | 6,053.69 mi (9,742.48 km) |
| Kastamonu to Orangeburg (South Carolina) | 5,806.63 mi (9,344.86 km) |
