| Saint-Gregoire to Opwijk | 327.01 mi (526.28 km) |
| Saint-Gregoire to Ostend | 295.71 mi (475.90 km) |
| Saint-Gregoire to Oud-Heverlee | 339.87 mi (546.96 km) |
| Saint-Gregoire to Oud-Turnhout | 369.29 mi (594.31 km) |
| Saint-Gregoire to Oudenaarde | 301.60 mi (485.37 km) |
| Saint-Gregoire to Oudenburg | 296.21 mi (476.70 km) |
| Saint-Gregoire to Oupeye | 373.51 mi (601.11 km) |
| Saint-Gregoire to Overijse | 333.09 mi (536.06 km) |
| Saint-Gregoire to Overpelt | 381.42 mi (613.84 km) |
| Saint-Gregoire to Paal | 366.07 mi (589.14 km) |
| Saint-Gregoire to Peer | 379.86 mi (611.32 km) |
| Saint-Gregoire to Pepinster | 376.40 mi (605.76 km) |
| Saint-Gregoire to Peruwelz | 287.99 mi (463.48 km) |
| Saint-Gregoire to Perwez | 338.48 mi (544.73 km) |
| Saint-Gregoire to Philippeville | 315.11 mi (507.13 km) |
