| Alcacer do Sal to Octeville | 848.40 mi (1,365.36 km) |
| Alcacer do Sal to Oignies | 1,007.88 mi (1,622.03 km) |
| Alcacer do Sal to Oissel | 894.72 mi (1,439.91 km) |
| Alcacer do Sal to Olivet | 838.62 mi (1,349.63 km) |
| Alcacer do Sal to Ollioules | 819.19 mi (1,318.35 km) |
| Alcacer do Sal to Olonne-sur-Mer | 659.90 mi (1,062.01 km) |
| Alcacer do Sal to Oloron-Sainte-Marie | 530.72 mi (854.11 km) |
| Alcacer do Sal to Onet Village | 708.31 mi (1,139.92 km) |
| Alcacer do Sal to Onnaing | 1,020.38 mi (1,642.14 km) |
| Alcacer do Sal to Orange | 797.09 mi (1,282.80 km) |
| Alcacer do Sal to Orchies | 1,015.07 mi (1,633.60 km) |
| Alcacer do Sal to Orleans | 840.85 mi (1,353.22 km) |
| Alcacer do Sal to Orly | 899.03 mi (1,446.85 km) |
| Alcacer do Sal to Ormesson-sur-Marne | 905.58 mi (1,457.40 km) |
| Alcacer do Sal to Orsay | 890.51 mi (1,433.13 km) |
