| South Milwaukee to Oerlinghausen | 4,213.92 mi (6,781.65 km) |
| South Milwaukee to Oestrich-Winkel | 4,265.74 mi (6,865.04 km) |
| South Milwaukee to Offenburg | 4,323.27 mi (6,957.64 km) |
| South Milwaukee to Oftersheim | 4,311.91 mi (6,939.34 km) |
| South Milwaukee to Ohrdruf | 4,331.89 mi (6,971.50 km) |
| South Milwaukee to Ohringen | 4,352.43 mi (7,004.57 km) |
| South Milwaukee to Olbernhau | 4,430.20 mi (7,129.72 km) |
| South Milwaukee to Olching | 4,460.08 mi (7,177.80 km) |
| South Milwaukee to Oldenburg | 4,153.39 mi (6,684.24 km) |
| South Milwaukee to Oldenburg in Holstein | 4,200.50 mi (6,760.06 km) |
| South Milwaukee to Olfen | 4,177.66 mi (6,723.30 km) |
| South Milwaukee to Olpe | 4,220.46 mi (6,792.18 km) |
| South Milwaukee to Olsberg | 4,231.08 mi (6,809.26 km) |
| South Milwaukee to Oranienburg | 4,340.95 mi (6,986.09 km) |
| South Milwaukee to Ortenberg | 4,290.36 mi (6,904.67 km) |
