| Boulder to Octeville | 4,704.18 mi (7,570.65 km) |
| Boulder to Oignies | 4,830.63 mi (7,774.14 km) |
| Boulder to Oissel | 4,813.51 mi (7,746.60 km) |
| Boulder to Olivet | 4,906.37 mi (7,896.04 km) |
| Boulder to Ollioules | 5,264.64 mi (8,472.62 km) |
| Boulder to Olonne-sur-Mer | 4,828.22 mi (7,770.27 km) |
| Boulder to Oloron-Sainte-Marie | 5,016.16 mi (8,072.73 km) |
| Boulder to Onet Village | 5,087.00 mi (8,186.73 km) |
| Boulder to Onnaing | 4,854.75 mi (7,812.96 km) |
| Boulder to Orange | 5,179.85 mi (8,336.16 km) |
| Boulder to Orchies | 4,838.91 mi (7,787.47 km) |
| Boulder to Orleans | 4,904.98 mi (7,893.80 km) |
| Boulder to Orly | 4,885.33 mi (7,862.18 km) |
| Boulder to Ormesson-sur-Marne | 4,888.61 mi (7,867.46 km) |
| Boulder to Orsay | 4,880.09 mi (7,853.75 km) |
