| Webster Groves to Oerlinghausen | 4,521.05 mi (7,275.92 km) |
| Webster Groves to Oestrich-Winkel | 4,568.65 mi (7,352.53 km) |
| Webster Groves to Offenburg | 4,623.05 mi (7,440.08 km) |
| Webster Groves to Oftersheim | 4,614.07 mi (7,425.64 km) |
| Webster Groves to Ohrdruf | 4,638.51 mi (7,464.97 km) |
| Webster Groves to Ohringen | 4,655.06 mi (7,491.59 km) |
| Webster Groves to Olbernhau | 4,738.53 mi (7,625.93 km) |
| Webster Groves to Olching | 4,762.40 mi (7,664.35 km) |
| Webster Groves to Oldenburg | 4,462.29 mi (7,181.36 km) |
| Webster Groves to Oldenburg in Holstein | 4,512.95 mi (7,262.88 km) |
| Webster Groves to Olfen | 4,483.40 mi (7,215.33 km) |
| Webster Groves to Olpe | 4,525.21 mi (7,282.62 km) |
| Webster Groves to Olsberg | 4,536.94 mi (7,301.50 km) |
| Webster Groves to Oranienburg | 4,652.50 mi (7,487.47 km) |
| Webster Groves to Ortenberg | 4,594.82 mi (7,394.64 km) |
