| Romeoville to Smolyan | 5,322.90 mi (8,566.38 km) |
| Romeoville to Sofia | 5,218.76 mi (8,398.78 km) |
| Romeoville to Sopot | 5,272.66 mi (8,485.53 km) |
| Romeoville to Sozopol | 5,389.11 mi (8,672.93 km) |
| Romeoville to Sredets | 5,374.85 mi (8,649.98 km) |
| Romeoville to Stamboliyski | 5,289.99 mi (8,513.42 km) |
| Romeoville to Stara Zagora | 5,315.60 mi (8,554.63 km) |
| Romeoville to Svilengrad | 5,368.23 mi (8,639.34 km) |
| Romeoville to Svishtov | 5,246.90 mi (8,444.07 km) |
| Romeoville to Targovishte | 5,308.39 mi (8,543.03 km) |
| Romeoville to Teteven | 5,242.28 mi (8,436.63 km) |
| Romeoville to Troyan | 5,260.10 mi (8,465.31 km) |
| Romeoville to Tryavna | 5,288.94 mi (8,511.73 km) |
| Romeoville to Tutrakan | 5,269.99 mi (8,481.22 km) |
| Romeoville to Varna | 5,356.55 mi (8,620.53 km) |
