| South Portland to Sierpc | 3,910.33 mi (6,293.07 km) |
| South Portland to Skarzysko-Kamienna | 4,018.42 mi (6,467.03 km) |
| South Portland to Skawina | 4,018.92 mi (6,467.82 km) |
| South Portland to Skierniewice | 3,959.85 mi (6,372.77 km) |
| South Portland to Skoczow | 3,985.75 mi (6,414.45 km) |
| South Portland to Skwierzyna | 3,766.90 mi (6,062.24 km) |
| South Portland to Slawno | 3,753.96 mi (6,041.42 km) |
| South Portland to Slubice | 3,739.96 mi (6,018.89 km) |
| South Portland to Slupca | 3,864.44 mi (6,219.22 km) |
| South Portland to Slupsk | 3,763.22 mi (6,056.32 km) |
| South Portland to Sochaczew | 3,953.51 mi (6,362.56 km) |
| South Portland to Sokolka | 4,028.33 mi (6,482.96 km) |
| South Portland to Sokolow Podlaski | 4,020.46 mi (6,470.30 km) |
| South Portland to Solec Kujawski | 3,851.60 mi (6,198.55 km) |
| South Portland to Sopot | 3,818.36 mi (6,145.05 km) |
