| Effingham to Orbetello | 4,892.58 mi (7,873.85 km) |
| Effingham to Oria | 5,237.14 mi (8,428.36 km) |
| Effingham to Oristano | 4,883.80 mi (7,859.71 km) |
| Effingham to Orta Nova | 5,123.09 mi (8,244.82 km) |
| Effingham to Orte | 4,939.98 mi (7,950.13 km) |
| Effingham to Ortona | 5,026.52 mi (8,089.40 km) |
| Effingham to Orvieto | 4,918.10 mi (7,914.92 km) |
| Effingham to Orzinuovi | 4,722.74 mi (7,600.52 km) |
| Effingham to Osimo | 4,942.19 mi (7,953.69 km) |
| Effingham to Ospitaletto | 4,722.28 mi (7,599.78 km) |
| Effingham to Ostuni | 5,224.82 mi (8,408.53 km) |
| Effingham to Ottaviano | 5,093.28 mi (8,196.84 km) |
| Effingham to Ovada | 4,700.20 mi (7,564.25 km) |
| Effingham to Ozieri | 4,874.36 mi (7,844.53 km) |
| Effingham to Paceco | 5,133.74 mi (8,261.96 km) |
