| Merrillville to Nuth | 4,201.70 mi (6,761.98 km) |
| Merrillville to Oegstgeest | 4,105.01 mi (6,606.38 km) |
| Merrillville to Oirschot | 4,159.41 mi (6,693.92 km) |
| Merrillville to Oisterwijk | 4,152.79 mi (6,683.28 km) |
| Merrillville to Oldebroek | 4,148.29 mi (6,676.03 km) |
| Merrillville to Oldenzaal | 4,190.48 mi (6,743.92 km) |
| Merrillville to Ommen | 4,164.70 mi (6,702.44 km) |
| Merrillville to Oosterend | 4,135.06 mi (6,654.74 km) |
| Merrillville to Oosterhout | 4,137.99 mi (6,659.45 km) |
| Merrillville to Oosterwolde | 4,143.61 mi (6,668.50 km) |
| Merrillville to Oostzaan | 4,111.78 mi (6,617.26 km) |
| Merrillville to Opmeer | 4,105.10 mi (6,606.52 km) |
| Merrillville to Oss | 4,158.10 mi (6,691.82 km) |
| Merrillville to Oud-Beijerland | 4,115.06 mi (6,622.55 km) |
| Merrillville to Oudenbosch | 4,127.48 mi (6,642.53 km) |
