| Trondheim to Orbetello | 1,450.66 mi (2,334.61 km) |
| Trondheim to Oria | 1,611.62 mi (2,593.65 km) |
| Trondheim to Oristano | 1,627.03 mi (2,618.44 km) |
| Trondheim to Orta Nova | 1,542.03 mi (2,481.66 km) |
| Trondheim to Orte | 1,451.05 mi (2,335.24 km) |
| Trondheim to Ortona | 1,465.33 mi (2,358.23 km) |
| Trondheim to Orvieto | 1,432.67 mi (2,305.66 km) |
| Trondheim to Orzinuovi | 1,245.86 mi (2,005.02 km) |
| Trondheim to Osimo | 1,383.63 mi (2,226.73 km) |
| Trondheim to Ospitaletto | 1,235.06 mi (1,987.64 km) |
| Trondheim to Ostuni | 1,595.29 mi (2,567.37 km) |
| Trondheim to Ottaviano | 1,568.94 mi (2,524.97 km) |
| Trondheim to Ovada | 1,300.11 mi (2,092.33 km) |
| Trondheim to Ozieri | 1,579.44 mi (2,541.87 km) |
| Trondheim to Paceco | 1,760.48 mi (2,833.21 km) |
