| Niagara Falls to Opole | 4,270.54 mi (6,872.76 km) |
| Niagara Falls to Orzesze | 4,320.47 mi (6,953.13 km) |
| Niagara Falls to Osowa | 4,144.07 mi (6,669.24 km) |
| Niagara Falls to Ostroda | 4,222.44 mi (6,795.36 km) |
| Niagara Falls to Ostroleka | 4,301.54 mi (6,922.66 km) |
| Niagara Falls to Ostrow Mazowiecka | 4,323.60 mi (6,958.16 km) |
| Niagara Falls to Ostrow Wielkopolski | 4,227.98 mi (6,804.28 km) |
| Niagara Falls to Ostrowiec Swietokrzyski | 4,382.86 mi (7,053.54 km) |
| Niagara Falls to Ostrzeszow | 4,241.18 mi (6,825.53 km) |
| Niagara Falls to Oswiecim | 4,341.97 mi (6,987.73 km) |
| Niagara Falls to Otwock | 4,329.84 mi (6,968.20 km) |
| Niagara Falls to Ozarow Mazowiecki | 4,309.76 mi (6,935.89 km) |
| Niagara Falls to Ozimek | 4,280.35 mi (6,888.56 km) |
| Niagara Falls to Ozorkow | 4,267.19 mi (6,867.37 km) |
| Niagara Falls to Pabianice | 4,283.24 mi (6,893.20 km) |
