| Horizon West to Orbetello | 5,056.18 mi (8,137.14 km) |
| Horizon West to Oria | 5,413.77 mi (8,712.62 km) |
| Horizon West to Oristano | 4,999.28 mi (8,045.57 km) |
| Horizon West to Orta Nova | 5,298.31 mi (8,526.80 km) |
| Horizon West to Orte | 5,110.35 mi (8,224.32 km) |
| Horizon West to Ortona | 5,206.86 mi (8,379.63 km) |
| Horizon West to Orvieto | 5,090.28 mi (8,192.02 km) |
| Horizon West to Orzinuovi | 4,918.74 mi (7,915.94 km) |
| Horizon West to Osimo | 5,131.80 mi (8,258.83 km) |
| Horizon West to Ospitaletto | 4,921.05 mi (7,919.66 km) |
| Horizon West to Ostuni | 5,403.98 mi (8,696.87 km) |
| Horizon West to Ottaviano | 5,255.15 mi (8,457.34 km) |
| Horizon West to Ovada | 4,879.54 mi (7,852.85 km) |
| Horizon West to Ozieri | 5,001.22 mi (8,048.68 km) |
| Horizon West to Paceco | 5,247.60 mi (8,445.20 km) |
