| SeaTac to Smolyan | 5,962.29 mi (9,595.37 km) |
| SeaTac to Sofia | 5,864.40 mi (9,437.83 km) |
| SeaTac to Sopot | 5,894.74 mi (9,486.66 km) |
| SeaTac to Sozopol | 5,962.98 mi (9,596.50 km) |
| SeaTac to Sredets | 5,958.60 mi (9,589.44 km) |
| SeaTac to Stamboliyski | 5,923.81 mi (9,533.45 km) |
| SeaTac to Stara Zagora | 5,925.38 mi (9,535.97 km) |
| SeaTac to Svilengrad | 5,978.47 mi (9,621.41 km) |
| SeaTac to Svishtov | 5,843.67 mi (9,404.47 km) |
| SeaTac to Targovishte | 5,889.43 mi (9,478.12 km) |
| SeaTac to Teteven | 5,868.52 mi (9,444.47 km) |
| SeaTac to Troyan | 5,879.13 mi (9,461.55 km) |
| SeaTac to Tryavna | 5,894.69 mi (9,486.58 km) |
| SeaTac to Tutrakan | 5,838.25 mi (9,395.76 km) |
| SeaTac to Varna | 5,914.67 mi (9,518.74 km) |
