| Ontario to Olivares | 5,824.37 mi (9,373.42 km) |
| Ontario to Olivenza | 5,729.07 mi (9,220.04 km) |
| Ontario to Olot | 5,949.12 mi (9,574.19 km) |
| Ontario to Onate | 5,725.47 mi (9,214.26 km) |
| Ontario to Onda | 5,949.77 mi (9,575.23 km) |
| Ontario to Onteniente | 5,989.34 mi (9,638.91 km) |
| Ontario to Orihuela | 6,009.92 mi (9,672.04 km) |
| Ontario to Osuna | 5,876.95 mi (9,458.04 km) |
| Ontario to Ourense | 5,541.84 mi (8,918.73 km) |
| Ontario to Oviedo | 5,578.42 mi (8,977.60 km) |
| Ontario to Paiporta | 5,968.63 mi (9,605.59 km) |
| Ontario to Pajara | 5,839.83 mi (9,398.29 km) |
| Ontario to Palafolls | 5,983.46 mi (9,629.45 km) |
| Ontario to Palafrugell | 5,986.66 mi (9,634.59 km) |
| Ontario to Palamos | 5,988.87 mi (9,638.15 km) |
