| Ames to Oerlinghausen | 1,018.48 mi (1,639.08 km) |
| Ames to Oestrich-Winkel | 928.36 mi (1,494.04 km) |
| Ames to Offenburg | 884.89 mi (1,424.10 km) |
| Ames to Oftersheim | 934.74 mi (1,504.32 km) |
| Ames to Ohrdruf | 1,061.56 mi (1,708.42 km) |
| Ames to Ohringen | 969.06 mi (1,559.55 km) |
| Ames to Olbernhau | 1,163.51 mi (1,872.49 km) |
| Ames to Olching | 1,028.75 mi (1,655.61 km) |
| Ames to Oldenburg | 1,047.42 mi (1,685.66 km) |
| Ames to Oldenburg in Holstein | 1,182.60 mi (1,903.21 km) |
| Ames to Olfen | 962.87 mi (1,549.59 km) |
| Ames to Olpe | 954.37 mi (1,535.90 km) |
| Ames to Olsberg | 990.21 mi (1,593.58 km) |
| Ames to Oranienburg | 1,214.12 mi (1,953.94 km) |
| Ames to Ortenberg | 981.07 mi (1,578.88 km) |
