| Trentham to Orbetello | 954.65 mi (1,536.36 km) |
| Trentham to Oria | 1,266.18 mi (2,037.72 km) |
| Trentham to Oristano | 1,035.63 mi (1,666.68 km) |
| Trentham to Orta Nova | 1,157.53 mi (1,862.87 km) |
| Trentham to Orte | 989.33 mi (1,592.17 km) |
| Trentham to Ortona | 1,060.17 mi (1,706.18 km) |
| Trentham to Orvieto | 966.65 mi (1,555.67 km) |
| Trentham to Orzinuovi | 755.14 mi (1,215.28 km) |
| Trentham to Osimo | 970.73 mi (1,562.24 km) |
| Trentham to Ospitaletto | 751.76 mi (1,209.84 km) |
| Trentham to Ostuni | 1,252.25 mi (2,015.30 km) |
| Trentham to Ottaviano | 1,143.34 mi (1,840.03 km) |
| Trentham to Ovada | 756.11 mi (1,216.84 km) |
| Trentham to Ozieri | 1,003.53 mi (1,615.03 km) |
| Trentham to Paceco | 1,252.32 mi (2,015.41 km) |
