| Watertown Town to Orbetello | 4,021.16 mi (6,471.43 km) |
| Watertown Town to Oria | 4,373.54 mi (7,038.53 km) |
| Watertown Town to Oristano | 3,993.02 mi (6,426.15 km) |
| Watertown Town to Orta Nova | 4,258.20 mi (6,852.91 km) |
| Watertown Town to Orte | 4,071.84 mi (6,552.99 km) |
| Watertown Town to Ortona | 4,163.44 mi (6,700.40 km) |
| Watertown Town to Orvieto | 4,050.65 mi (6,518.89 km) |
| Watertown Town to Orzinuovi | 3,865.34 mi (6,220.66 km) |
| Watertown Town to Osimo | 4,082.99 mi (6,570.94 km) |
| Watertown Town to Ospitaletto | 3,866.24 mi (6,222.11 km) |
| Watertown Town to Ostuni | 4,362.32 mi (7,020.47 km) |
| Watertown Town to Ottaviano | 4,222.26 mi (6,795.07 km) |
| Watertown Town to Ovada | 3,834.72 mi (6,171.38 km) |
| Watertown Town to Ozieri | 3,987.77 mi (6,417.70 km) |
| Watertown Town to Paceco | 4,243.77 mi (6,829.68 km) |
