| Dundalk to Octeville | 3,604.79 mi (5,801.35 km) |
| Dundalk to Oignies | 3,778.19 mi (6,080.41 km) |
| Dundalk to Oissel | 3,726.93 mi (5,997.92 km) |
| Dundalk to Olivet | 3,798.70 mi (6,113.42 km) |
| Dundalk to Ollioules | 4,108.45 mi (6,611.91 km) |
| Dundalk to Olonne-sur-Mer | 3,672.14 mi (5,909.74 km) |
| Dundalk to Oloron-Sainte-Marie | 3,813.18 mi (6,136.72 km) |
| Dundalk to Onet Village | 3,925.40 mi (6,317.33 km) |
| Dundalk to Onnaing | 3,805.02 mi (6,123.59 km) |
| Dundalk to Orange | 4,031.24 mi (6,487.66 km) |
| Dundalk to Orchies | 3,788.33 mi (6,096.73 km) |
| Dundalk to Orleans | 3,798.06 mi (6,112.38 km) |
| Dundalk to Orly | 3,796.86 mi (6,110.46 km) |
| Dundalk to Ormesson-sur-Marne | 3,801.93 mi (6,118.61 km) |
| Dundalk to Orsay | 3,789.35 mi (6,098.37 km) |
