| Marlow to Orbetello | 844.77 mi (1,359.53 km) |
| Marlow to Oria | 1,162.46 mi (1,870.80 km) |
| Marlow to Oristano | 922.26 mi (1,484.24 km) |
| Marlow to Orta Nova | 1,052.37 mi (1,693.62 km) |
| Marlow to Orte | 881.10 mi (1,417.99 km) |
| Marlow to Ortona | 954.84 mi (1,536.67 km) |
| Marlow to Orvieto | 858.43 mi (1,381.50 km) |
| Marlow to Orzinuovi | 648.80 mi (1,044.14 km) |
| Marlow to Osimo | 866.26 mi (1,394.11 km) |
| Marlow to Ospitaletto | 646.13 mi (1,039.85 km) |
| Marlow to Ostuni | 1,148.88 mi (1,848.94 km) |
| Marlow to Ottaviano | 1,035.63 mi (1,666.69 km) |
| Marlow to Ovada | 645.87 mi (1,039.43 km) |
| Marlow to Ozieri | 890.40 mi (1,432.96 km) |
| Marlow to Paceco | 1,140.08 mi (1,834.79 km) |
