| Upminster to Orbetello | 812.78 mi (1,308.04 km) |
| Upminster to Oria | 1,125.58 mi (1,811.44 km) |
| Upminster to Oristano | 898.47 mi (1,445.95 km) |
| Upminster to Orta Nova | 1,016.34 mi (1,635.64 km) |
| Upminster to Orte | 847.40 mi (1,363.76 km) |
| Upminster to Ortona | 918.91 mi (1,478.83 km) |
| Upminster to Orvieto | 824.72 mi (1,327.25 km) |
| Upminster to Orzinuovi | 613.50 mi (987.33 km) |
| Upminster to Osimo | 829.75 mi (1,335.36 km) |
| Upminster to Ospitaletto | 610.31 mi (982.20 km) |
| Upminster to Ostuni | 1,111.80 mi (1,789.27 km) |
| Upminster to Ottaviano | 1,001.48 mi (1,611.73 km) |
| Upminster to Ovada | 614.36 mi (988.72 km) |
| Upminster to Ozieri | 864.94 mi (1,391.99 km) |
| Upminster to Paceco | 1,111.71 mi (1,789.13 km) |
