| Mason City to Olivares | 4,391.11 mi (7,066.81 km) |
| Mason City to Olivenza | 4,298.38 mi (6,917.57 km) |
| Mason City to Olot | 4,564.91 mi (7,346.52 km) |
| Mason City to Onate | 4,328.73 mi (6,966.41 km) |
| Mason City to Onda | 4,543.33 mi (7,311.79 km) |
| Mason City to Onteniente | 4,576.22 mi (7,364.72 km) |
| Mason City to Orihuela | 4,592.42 mi (7,390.78 km) |
| Mason City to Osuna | 4,445.33 mi (7,154.07 km) |
| Mason City to Ourense | 4,125.28 mi (6,638.99 km) |
| Mason City to Oviedo | 4,172.84 mi (6,715.53 km) |
| Mason City to Paiporta | 4,559.02 mi (7,337.04 km) |
| Mason City to Pajara | 4,387.55 mi (7,061.08 km) |
| Mason City to Palafolls | 4,597.18 mi (7,398.45 km) |
| Mason City to Palafrugell | 4,603.47 mi (7,408.58 km) |
| Mason City to Palamos | 4,605.12 mi (7,411.22 km) |
