| Duluth to Nuth | 4,121.04 mi (6,632.18 km) |
| Duluth to Oegstgeest | 4,019.48 mi (6,468.74 km) |
| Duluth to Oirschot | 4,076.36 mi (6,560.27 km) |
| Duluth to Oisterwijk | 4,069.45 mi (6,549.14 km) |
| Duluth to Oldebroek | 4,056.61 mi (6,528.49 km) |
| Duluth to Oldenzaal | 4,096.69 mi (6,592.98 km) |
| Duluth to Ommen | 4,071.02 mi (6,551.68 km) |
| Duluth to Oosterend | 4,038.92 mi (6,500.01 km) |
| Duluth to Oosterhout | 4,055.24 mi (6,526.29 km) |
| Duluth to Oosterwolde | 4,046.91 mi (6,512.87 km) |
| Duluth to Oostzaan | 4,023.20 mi (6,474.72 km) |
| Duluth to Opmeer | 4,014.39 mi (6,460.54 km) |
| Duluth to Oss | 4,072.48 mi (6,554.03 km) |
| Duluth to Oud-Beijerland | 4,032.42 mi (6,489.55 km) |
| Duluth to Oudenbosch | 4,046.12 mi (6,511.60 km) |
