| Prospect Heights to Nuth | 4,194.05 mi (6,749.67 km) |
| Prospect Heights to Oegstgeest | 4,096.68 mi (6,592.96 km) |
| Prospect Heights to Oirschot | 4,151.43 mi (6,681.08 km) |
| Prospect Heights to Oisterwijk | 4,144.77 mi (6,670.36 km) |
| Prospect Heights to Oldebroek | 4,139.23 mi (6,661.45 km) |
| Prospect Heights to Oldenzaal | 4,181.20 mi (6,728.99 km) |
| Prospect Heights to Ommen | 4,155.41 mi (6,687.49 km) |
| Prospect Heights to Oosterend | 4,125.45 mi (6,639.27 km) |
| Prospect Heights to Oosterhout | 4,130.03 mi (6,646.64 km) |
| Prospect Heights to Oosterwolde | 4,133.94 mi (6,652.93 km) |
| Prospect Heights to Oostzaan | 4,103.07 mi (6,603.26 km) |
| Prospect Heights to Opmeer | 4,096.13 mi (6,592.08 km) |
| Prospect Heights to Oss | 4,149.80 mi (6,678.46 km) |
| Prospect Heights to Oud-Beijerland | 4,107.09 mi (6,609.72 km) |
| Prospect Heights to Oudenbosch | 4,119.67 mi (6,629.98 km) |
