| Wilmette to Olivares | 4,175.17 mi (6,719.29 km) |
| Wilmette to Olivenza | 4,084.90 mi (6,574.01 km) |
| Wilmette to Olot | 4,379.89 mi (7,048.75 km) |
| Wilmette to Onate | 4,138.01 mi (6,659.48 km) |
| Wilmette to Onda | 4,345.79 mi (6,993.88 km) |
| Wilmette to Onteniente | 4,374.34 mi (7,039.82 km) |
| Wilmette to Orihuela | 4,387.58 mi (7,061.12 km) |
| Wilmette to Osuna | 4,230.58 mi (6,808.47 km) |
| Wilmette to Ourense | 3,923.05 mi (6,313.54 km) |
| Wilmette to Oviedo | 3,977.59 mi (6,401.32 km) |
| Wilmette to Paiporta | 4,359.45 mi (7,015.85 km) |
| Wilmette to Pajara | 4,134.90 mi (6,654.48 km) |
| Wilmette to Palafolls | 4,410.88 mi (7,098.62 km) |
| Wilmette to Palafrugell | 4,418.78 mi (7,111.35 km) |
| Wilmette to Palamos | 4,420.12 mi (7,113.50 km) |
