| Dubuque to Opwijk | 4,212.90 mi (6,780.01 km) |
| Dubuque to Ostend | 4,157.01 mi (6,690.06 km) |
| Dubuque to Oud-Heverlee | 4,235.59 mi (6,816.52 km) |
| Dubuque to Oud-Turnhout | 4,228.81 mi (6,805.62 km) |
| Dubuque to Oudenaarde | 4,195.87 mi (6,752.61 km) |
| Dubuque to Oudenburg | 4,161.52 mi (6,697.33 km) |
| Dubuque to Oupeye | 4,275.93 mi (6,881.44 km) |
| Dubuque to Overijse | 4,232.60 mi (6,811.71 km) |
| Dubuque to Overpelt | 4,248.27 mi (6,836.92 km) |
| Dubuque to Paal | 4,246.20 mi (6,833.59 km) |
| Dubuque to Peer | 4,252.80 mi (6,844.22 km) |
| Dubuque to Pepinster | 4,287.70 mi (6,900.39 km) |
| Dubuque to Peruwelz | 4,207.68 mi (6,771.60 km) |
| Dubuque to Perwez | 4,248.94 mi (6,838.01 km) |
| Dubuque to Philippeville | 4,255.33 mi (6,848.29 km) |
