| Niagara Falls to Orthez | 3,778.18 mi (6,080.39 km) |
| Niagara Falls to Orvault | 3,621.22 mi (5,827.78 km) |
| Niagara Falls to Osny | 3,718.81 mi (5,984.85 km) |
| Niagara Falls to Ostwald | 3,961.79 mi (6,375.88 km) |
| Niagara Falls to Ouistreham | 3,617.90 mi (5,822.44 km) |
| Niagara Falls to Oullins | 3,941.66 mi (6,343.49 km) |
| Niagara Falls to Outreau | 3,650.28 mi (5,874.57 km) |
| Niagara Falls to Oyonnax | 3,958.06 mi (6,369.88 km) |
| Niagara Falls to Ozoir-la-Ferriere | 3,752.61 mi (6,039.24 km) |
| Niagara Falls to Pace | 3,588.73 mi (5,775.50 km) |
| Niagara Falls to Palaiseau | 3,736.99 mi (6,014.10 km) |
| Niagara Falls to Pamiers | 3,895.08 mi (6,268.53 km) |
| Niagara Falls to Panazol | 3,790.34 mi (6,099.96 km) |
| Niagara Falls to Pantin | 3,737.61 mi (6,015.10 km) |
| Niagara Falls to Paray-le-Monial | 3,887.78 mi (6,256.77 km) |
