| South Portland to Nyon | 3,591.58 mi (5,780.10 km) |
| South Portland to Oberriet | 3,702.23 mi (5,958.16 km) |
| South Portland to Obersiggenthal | 3,643.88 mi (5,864.25 km) |
| South Portland to Oberwil | 3,612.31 mi (5,813.45 km) |
| South Portland to Oberwingert | 3,662.75 mi (5,894.63 km) |
| South Portland to Oftringen | 3,633.54 mi (5,847.62 km) |
| South Portland to Olten | 3,631.81 mi (5,844.83 km) |
| South Portland to Onex | 3,592.11 mi (5,780.95 km) |
| South Portland to Opfikon | 3,656.99 mi (5,885.35 km) |
| South Portland to Ostermundigen | 3,626.93 mi (5,836.99 km) |
| South Portland to Payerne | 3,607.81 mi (5,806.21 km) |
| South Portland to Pfaffikon | 3,668.10 mi (5,903.23 km) |
| South Portland to Plan-les-Ouates | 3,593.34 mi (5,782.93 km) |
| South Portland to Pratteln | 3,618.28 mi (5,823.05 km) |
| South Portland to Prilly | 3,602.51 mi (5,797.68 km) |
