| Great Missenden to Orbetello | 848.98 mi (1,366.29 km) |
| Great Missenden to Oria | 1,165.11 mi (1,875.06 km) |
| Great Missenden to Oristano | 928.42 mi (1,494.15 km) |
| Great Missenden to Orta Nova | 1,055.32 mi (1,698.38 km) |
| Great Missenden to Orte | 884.80 mi (1,423.95 km) |
| Great Missenden to Ortona | 957.82 mi (1,541.46 km) |
| Great Missenden to Orvieto | 862.12 mi (1,387.46 km) |
| Great Missenden to Orzinuovi | 651.95 mi (1,049.21 km) |
| Great Missenden to Osimo | 869.02 mi (1,398.56 km) |
| Great Missenden to Ospitaletto | 649.11 mi (1,044.64 km) |
| Great Missenden to Ostuni | 1,151.45 mi (1,853.08 km) |
| Great Missenden to Ottaviano | 1,039.21 mi (1,672.45 km) |
| Great Missenden to Ovada | 650.17 mi (1,046.35 km) |
| Great Missenden to Ozieri | 896.21 mi (1,442.31 km) |
| Great Missenden to Paceco | 1,145.26 mi (1,843.12 km) |
