| Watertown to Oerlinghausen | 3,726.08 mi (5,996.55 km) |
| Watertown to Oestrich-Winkel | 3,764.31 mi (6,058.08 km) |
| Watertown to Offenburg | 3,812.90 mi (6,136.27 km) |
| Watertown to Oftersheim | 3,808.17 mi (6,128.66 km) |
| Watertown to Ohrdruf | 3,841.90 mi (6,182.93 km) |
| Watertown to Ohringen | 3,849.89 mi (6,195.79 km) |
| Watertown to Olbernhau | 3,945.72 mi (6,350.03 km) |
| Watertown to Olching | 3,956.34 mi (6,367.11 km) |
| Watertown to Oldenburg | 3,672.14 mi (5,909.74 km) |
| Watertown to Oldenburg in Holstein | 3,733.19 mi (6,007.99 km) |
| Watertown to Olfen | 3,685.31 mi (5,930.93 km) |
| Watertown to Olpe | 3,724.78 mi (5,994.45 km) |
| Watertown to Olsberg | 3,738.94 mi (6,017.25 km) |
| Watertown to Oranienburg | 3,869.17 mi (6,226.82 km) |
| Watertown to Ortenberg | 3,793.52 mi (6,105.07 km) |
