| Donaueschingen to Oria | 684.25 mi (1,101.20 km) |
| Donaueschingen to Oristano | 556.03 mi (894.85 km) |
| Donaueschingen to Orta Nova | 578.18 mi (930.49 km) |
| Donaueschingen to Orte | 423.84 mi (682.11 km) |
| Donaueschingen to Ortona | 481.80 mi (775.38 km) |
| Donaueschingen to Orvieto | 401.77 mi (646.59 km) |
| Donaueschingen to Orzinuovi | 188.97 mi (304.12 km) |
| Donaueschingen to Osimo | 391.09 mi (629.40 km) |
| Donaueschingen to Ospitaletto | 181.57 mi (292.21 km) |
| Donaueschingen to Ostuni | 670.01 mi (1,078.27 km) |
| Donaueschingen to Ottaviano | 572.16 mi (920.80 km) |
| Donaueschingen to Ovada | 229.07 mi (368.65 km) |
| Donaueschingen to Ozieri | 509.69 mi (820.27 km) |
| Donaueschingen to Paceco | 718.32 mi (1,156.02 km) |
| Donaueschingen to Pachino | 845.53 mi (1,360.75 km) |
