| Grand Haven to Orbetello | 4,628.36 mi (7,448.62 km) |
| Grand Haven to Oria | 4,969.20 mi (7,997.15 km) |
| Grand Haven to Oristano | 4,628.28 mi (7,448.50 km) |
| Grand Haven to Orta Nova | 4,855.87 mi (7,814.77 km) |
| Grand Haven to Orte | 4,674.38 mi (7,522.69 km) |
| Grand Haven to Ortona | 4,758.88 mi (7,658.67 km) |
| Grand Haven to Orvieto | 4,652.30 mi (7,487.16 km) |
| Grand Haven to Orzinuovi | 4,453.90 mi (7,167.86 km) |
| Grand Haven to Osimo | 4,673.41 mi (7,521.13 km) |
| Grand Haven to Ospitaletto | 4,453.00 mi (7,166.41 km) |
| Grand Haven to Ostuni | 4,956.52 mi (7,976.75 km) |
| Grand Haven to Ottaviano | 4,828.42 mi (7,770.59 km) |
| Grand Haven to Ovada | 4,434.22 mi (7,136.19 km) |
| Grand Haven to Ozieri | 4,616.78 mi (7,429.98 km) |
| Grand Haven to Paceco | 4,877.21 mi (7,849.11 km) |
