| Round Lake to Octeville | 3,947.48 mi (6,352.86 km) |
| Round Lake to Oignies | 4,097.48 mi (6,594.26 km) |
| Round Lake to Oissel | 4,064.07 mi (6,540.50 km) |
| Round Lake to Olivet | 4,148.18 mi (6,675.85 km) |
| Round Lake to Ollioules | 4,487.67 mi (7,222.21 km) |
| Round Lake to Olonne-sur-Mer | 4,047.04 mi (6,513.09 km) |
| Round Lake to Oloron-Sainte-Marie | 4,215.84 mi (6,784.75 km) |
| Round Lake to Onet Village | 4,305.88 mi (6,929.65 km) |
| Round Lake to Onnaing | 4,123.20 mi (6,635.64 km) |
| Round Lake to Orange | 4,405.57 mi (7,090.08 km) |
| Round Lake to Orchies | 4,106.75 mi (6,609.18 km) |
| Round Lake to Orleans | 4,147.12 mi (6,674.15 km) |
| Round Lake to Orly | 4,135.85 mi (6,656.01 km) |
| Round Lake to Ormesson-sur-Marne | 4,140.01 mi (6,662.70 km) |
| Round Lake to Orsay | 4,129.49 mi (6,645.78 km) |
