| Cities | Distance |
|---|---|
| Trets to Oria | 645.92 mi (1,039.50 km) |
| Trets to Oristano | 286.92 mi (461.75 km) |
| Trets to Orta Nova | 531.72 mi (855.72 km) |
| Trets to Orte | 345.52 mi (556.06 km) |
| Trets to Ortona | 447.32 mi (719.89 km) |
| Trets to Orvieto | 328.00 mi (527.87 km) |
| Trets to Orzinuovi | 249.23 mi (401.09 km) |
| Trets to Osimo | 390.89 mi (629.08 km) |
| Trets to Ospitaletto | 260.65 mi (419.48 km) |
| Trets to Ostuni | 637.53 mi (1,026.01 km) |
| Trets to Ottaviano | 484.48 mi (779.70 km) |
| Trets to Ovada | 168.53 mi (271.22 km) |
| Trets to Ozieri | 260.92 mi (419.91 km) |
| Trets to Paceco | 520.91 mi (838.33 km) |
| Trets to Pachino | 680.30 mi (1,094.83 km) |