| Mount Prospect to Olivares | 4,185.25 mi (6,735.51 km) |
| Mount Prospect to Olivenza | 4,094.92 mi (6,590.14 km) |
| Mount Prospect to Olot | 4,389.28 mi (7,063.87 km) |
| Mount Prospect to Onate | 4,147.53 mi (6,674.80 km) |
| Mount Prospect to Onda | 4,355.48 mi (7,009.47 km) |
| Mount Prospect to Onteniente | 4,384.13 mi (7,055.57 km) |
| Mount Prospect to Orihuela | 4,397.43 mi (7,076.98 km) |
| Mount Prospect to Osuna | 4,240.64 mi (6,824.65 km) |
| Mount Prospect to Ourense | 3,932.83 mi (6,329.27 km) |
| Mount Prospect to Oviedo | 3,987.21 mi (6,416.80 km) |
| Mount Prospect to Paiporta | 4,369.18 mi (7,031.52 km) |
| Mount Prospect to Pajara | 4,145.57 mi (6,671.66 km) |
| Mount Prospect to Palafolls | 4,420.30 mi (7,113.79 km) |
| Mount Prospect to Palafrugell | 4,428.17 mi (7,126.46 km) |
| Mount Prospect to Palamos | 4,429.52 mi (7,128.62 km) |
