| Greenock to Octeville | 455.82 mi (733.58 km) |
| Greenock to Oignies | 495.85 mi (798.00 km) |
| Greenock to Oissel | 517.97 mi (833.59 km) |
| Greenock to Olivet | 626.12 mi (1,007.64 km) |
| Greenock to Ollioules | 1,002.28 mi (1,613.01 km) |
| Greenock to Olonne-sur-Mer | 663.03 mi (1,067.04 km) |
| Greenock to Oloron-Sainte-Marie | 900.40 mi (1,449.06 km) |
| Greenock to Onet Village | 862.98 mi (1,388.84 km) |
| Greenock to Onnaing | 516.67 mi (831.49 km) |
| Greenock to Orange | 918.10 mi (1,477.53 km) |
| Greenock to Orchies | 502.29 mi (808.35 km) |
| Greenock to Orleans | 623.85 mi (1,003.99 km) |
| Greenock to Orly | 581.69 mi (936.15 km) |
| Greenock to Ormesson-sur-Marne | 582.34 mi (937.19 km) |
| Greenock to Orsay | 580.09 mi (933.56 km) |
