| Niagara Falls to Nyon | 3,977.42 mi (6,401.03 km) |
| Niagara Falls to Oberriet | 4,079.15 mi (6,564.76 km) |
| Niagara Falls to Obersiggenthal | 4,022.10 mi (6,472.94 km) |
| Niagara Falls to Oberwil | 3,991.55 mi (6,423.78 km) |
| Niagara Falls to Oberwingert | 4,040.10 mi (6,501.92 km) |
| Niagara Falls to Oftringen | 4,013.05 mi (6,458.38 km) |
| Niagara Falls to Olten | 4,011.20 mi (6,455.40 km) |
| Niagara Falls to Onex | 3,978.93 mi (6,403.47 km) |
| Niagara Falls to Opfikon | 4,035.00 mi (6,493.71 km) |
| Niagara Falls to Ostermundigen | 4,008.58 mi (6,451.18 km) |
| Niagara Falls to Payerne | 3,990.86 mi (6,422.67 km) |
| Niagara Falls to Pfaffikon | 4,046.05 mi (6,511.49 km) |
| Niagara Falls to Plan-les-Ouates | 3,980.20 mi (6,405.52 km) |
| Niagara Falls to Pratteln | 3,997.29 mi (6,433.01 km) |
| Niagara Falls to Prilly | 3,987.20 mi (6,416.78 km) |
