| Naperville to Smolyan | 5,319.64 mi (8,561.14 km) |
| Naperville to Sofia | 5,215.49 mi (8,393.52 km) |
| Naperville to Sopot | 5,269.29 mi (8,480.11 km) |
| Naperville to Sozopol | 5,385.54 mi (8,667.19 km) |
| Naperville to Sredets | 5,371.32 mi (8,644.31 km) |
| Naperville to Stamboliyski | 5,286.69 mi (8,508.11 km) |
| Naperville to Stara Zagora | 5,312.18 mi (8,549.13 km) |
| Naperville to Svilengrad | 5,364.84 mi (8,633.88 km) |
| Naperville to Svishtov | 5,243.39 mi (8,438.42 km) |
| Naperville to Targovishte | 5,304.82 mi (8,537.29 km) |
| Naperville to Teteven | 5,238.92 mi (8,431.22 km) |
| Naperville to Troyan | 5,256.71 mi (8,459.86 km) |
| Naperville to Tryavna | 5,285.49 mi (8,506.18 km) |
| Naperville to Tutrakan | 5,266.34 mi (8,475.35 km) |
| Naperville to Varna | 5,352.88 mi (8,614.63 km) |
