| Madison to Oerlinghausen | 4,259.35 mi (6,854.77 km) |
| Madison to Oestrich-Winkel | 4,313.48 mi (6,941.88 km) |
| Madison to Offenburg | 4,372.57 mi (7,036.97 km) |
| Madison to Oftersheim | 4,360.02 mi (7,016.77 km) |
| Madison to Ohrdruf | 4,377.56 mi (7,045.00 km) |
| Madison to Ohringen | 4,400.29 mi (7,081.59 km) |
| Madison to Olbernhau | 4,474.81 mi (7,201.51 km) |
| Madison to Olching | 4,508.04 mi (7,254.99 km) |
| Madison to Oldenburg | 4,197.77 mi (6,755.65 km) |
| Madison to Oldenburg in Holstein | 4,242.48 mi (6,827.61 km) |
| Madison to Olfen | 4,223.92 mi (6,797.74 km) |
| Madison to Olpe | 4,267.25 mi (6,867.47 km) |
| Madison to Olsberg | 4,277.23 mi (6,883.54 km) |
| Madison to Oranienburg | 4,383.50 mi (7,054.57 km) |
| Madison to Ortenberg | 4,337.28 mi (6,980.17 km) |
