| Flagstaff to Smolyan | 6,454.64 mi (10,387.74 km) |
| Flagstaff to Sofia | 6,351.21 mi (10,221.28 km) |
| Flagstaff to Sopot | 6,395.28 mi (10,292.20 km) |
| Flagstaff to Sozopol | 6,491.25 mi (10,446.66 km) |
| Flagstaff to Sredets | 6,481.45 mi (10,430.88 km) |
| Flagstaff to Stamboliyski | 6,418.46 mi (10,329.51 km) |
| Flagstaff to Stara Zagora | 6,433.34 mi (10,353.45 km) |
| Flagstaff to Svilengrad | 6,487.30 mi (10,440.31 km) |
| Flagstaff to Svishtov | 6,356.98 mi (10,230.57 km) |
| Flagstaff to Targovishte | 6,412.25 mi (10,319.52 km) |
| Flagstaff to Teteven | 6,366.20 mi (10,245.41 km) |
| Flagstaff to Troyan | 6,381.02 mi (10,269.26 km) |
| Flagstaff to Tryavna | 6,404.20 mi (10,306.56 km) |
| Flagstaff to Tutrakan | 6,366.82 mi (10,246.40 km) |
| Flagstaff to Varna | 6,450.32 mi (10,380.79 km) |
