| Helena to Oerlinghausen | 4,776.64 mi (7,687.25 km) |
| Helena to Oestrich-Winkel | 4,863.62 mi (7,827.24 km) |
| Helena to Offenburg | 4,944.04 mi (7,956.66 km) |
| Helena to Oftersheim | 4,913.88 mi (7,908.12 km) |
| Helena to Ohrdruf | 4,893.63 mi (7,875.54 km) |
| Helena to Ohringen | 4,948.74 mi (7,964.22 km) |
| Helena to Olbernhau | 4,970.84 mi (7,999.79 km) |
| Helena to Olching | 5,053.97 mi (8,133.58 km) |
| Helena to Oldenburg | 4,701.78 mi (7,566.79 km) |
| Helena to Oldenburg in Holstein | 4,708.67 mi (7,577.86 km) |
| Helena to Olfen | 4,755.04 mi (7,652.50 km) |
| Helena to Olpe | 4,804.64 mi (7,732.33 km) |
| Helena to Olsberg | 4,804.68 mi (7,732.39 km) |
| Helena to Oranienburg | 4,852.22 mi (7,808.90 km) |
| Helena to Ortenberg | 4,873.81 mi (7,843.64 km) |
