| Mason City to Norwich | 4,105.18 mi (6,606.65 km) |
| Mason City to Nottingham | 4,006.45 mi (6,447.76 km) |
| Mason City to Nuneaton | 4,010.20 mi (6,453.79 km) |
| Mason City to Oadby | 4,021.64 mi (6,472.21 km) |
| Mason City to Oakengates | 3,968.61 mi (6,386.86 km) |
| Mason City to Oakham | 4,031.42 mi (6,487.94 km) |
| Mason City to Oldbury | 3,991.00 mi (6,422.89 km) |
| Mason City to Oldham | 3,951.35 mi (6,359.08 km) |
| Mason City to Ollerton | 4,002.40 mi (6,441.23 km) |
| Mason City to Olton | 4,000.98 mi (6,438.95 km) |
| Mason City to Omagh | 3,732.21 mi (6,006.42 km) |
| Mason City to Ormesby | 3,949.78 mi (6,356.56 km) |
| Mason City to Ormskirk | 3,923.10 mi (6,313.62 km) |
| Mason City to Orpington | 4,108.56 mi (6,612.08 km) |
| Mason City to Ossett | 3,965.75 mi (6,382.26 km) |
