| Prospect Heights to Opole | 4,632.05 mi (7,454.57 km) |
| Prospect Heights to Orzesze | 4,682.51 mi (7,535.77 km) |
| Prospect Heights to Osowa | 4,487.18 mi (7,221.42 km) |
| Prospect Heights to Ostroda | 4,565.93 mi (7,348.16 km) |
| Prospect Heights to Ostroleka | 4,644.56 mi (7,474.70 km) |
| Prospect Heights to Ostrow Mazowiecka | 4,667.11 mi (7,510.99 km) |
| Prospect Heights to Ostrow Wielkopolski | 4,585.40 mi (7,379.48 km) |
| Prospect Heights to Ostrowiec Swietokrzyski | 4,735.80 mi (7,621.53 km) |
| Prospect Heights to Ostrzeszow | 4,599.40 mi (7,402.02 km) |
| Prospect Heights to Oswiecim | 4,703.49 mi (7,569.53 km) |
| Prospect Heights to Otwock | 4,677.83 mi (7,528.25 km) |
| Prospect Heights to Ozarow Mazowiecki | 4,658.32 mi (7,496.84 km) |
| Prospect Heights to Ozimek | 4,641.26 mi (7,469.38 km) |
| Prospect Heights to Ozorkow | 4,620.12 mi (7,435.36 km) |
| Prospect Heights to Pabianice | 4,637.38 mi (7,463.13 km) |
