| Monte Porzio Catone to Oegstgeest | 813.75 mi (1,309.60 km) |
| Monte Porzio Catone to Oirschot | 754.95 mi (1,214.98 km) |
| Monte Porzio Catone to Oisterwijk | 762.09 mi (1,226.47 km) |
| Monte Porzio Catone to Oldebroek | 800.65 mi (1,288.52 km) |
| Monte Porzio Catone to Oldenzaal | 774.24 mi (1,246.01 km) |
| Monte Porzio Catone to Ommen | 795.58 mi (1,280.36 km) |
| Monte Porzio Catone to Oosterend | 832.27 mi (1,339.41 km) |
| Monte Porzio Catone to Oosterhout | 773.25 mi (1,244.42 km) |
| Monte Porzio Catone to Oosterwolde | 827.61 mi (1,331.92 km) |
| Monte Porzio Catone to Oostzaan | 819.65 mi (1,319.11 km) |
| Monte Porzio Catone to Opmeer | 834.37 mi (1,342.80 km) |
| Monte Porzio Catone to Oss | 766.33 mi (1,233.29 km) |
| Monte Porzio Catone to Oud-Beijerland | 793.82 mi (1,277.53 km) |
| Monte Porzio Catone to Oudenbosch | 777.74 mi (1,251.65 km) |
| Monte Porzio Catone to Oudewater | 795.11 mi (1,279.61 km) |
