| San Felice Circeo to Oegstgeest | 858.44 mi (1,381.53 km) |
| San Felice Circeo to Oirschot | 799.64 mi (1,286.90 km) |
| San Felice Circeo to Oisterwijk | 806.78 mi (1,298.39 km) |
| San Felice Circeo to Oldebroek | 845.19 mi (1,360.20 km) |
| San Felice Circeo to Oldenzaal | 818.56 mi (1,317.34 km) |
| San Felice Circeo to Ommen | 840.00 mi (1,351.85 km) |
| San Felice Circeo to Oosterend | 876.68 mi (1,410.88 km) |
| San Felice Circeo to Oosterhout | 817.94 mi (1,316.35 km) |
| San Felice Circeo to Oosterwolde | 871.98 mi (1,403.31 km) |
| San Felice Circeo to Oostzaan | 864.32 mi (1,390.98 km) |
| San Felice Circeo to Opmeer | 879.01 mi (1,414.63 km) |
| San Felice Circeo to Oss | 810.99 mi (1,305.17 km) |
| San Felice Circeo to Oud-Beijerland | 838.51 mi (1,349.46 km) |
| San Felice Circeo to Oudenbosch | 822.43 mi (1,323.57 km) |
| San Felice Circeo to Oudewater | 839.80 mi (1,351.53 km) |
