| Romeoville to Octeville | 3,978.74 mi (6,403.17 km) |
| Romeoville to Oignies | 4,130.42 mi (6,647.26 km) |
| Romeoville to Oissel | 4,095.81 mi (6,591.57 km) |
| Romeoville to Olivet | 4,179.15 mi (6,725.70 km) |
| Romeoville to Ollioules | 4,516.78 mi (7,269.05 km) |
| Romeoville to Olonne-sur-Mer | 4,076.11 mi (6,559.87 km) |
| Romeoville to Oloron-Sainte-Marie | 4,242.93 mi (6,828.33 km) |
| Romeoville to Onet Village | 4,334.76 mi (6,976.11 km) |
| Romeoville to Onnaing | 4,156.22 mi (6,688.79 km) |
| Romeoville to Orange | 4,434.98 mi (7,137.40 km) |
| Romeoville to Orchies | 4,139.75 mi (6,662.28 km) |
| Romeoville to Orleans | 4,178.12 mi (6,724.04 km) |
| Romeoville to Orly | 4,167.53 mi (6,706.99 km) |
| Romeoville to Ormesson-sur-Marne | 4,171.75 mi (6,713.78 km) |
| Romeoville to Orsay | 4,161.08 mi (6,696.62 km) |
