| Viljandi to Smolyan | 1,160.28 mi (1,867.30 km) |
| Viljandi to Sofia | 1,086.89 mi (1,749.18 km) |
| Viljandi to Sopot | 1,086.54 mi (1,748.62 km) |
| Viljandi to Sozopol | 1,105.78 mi (1,779.58 km) |
| Viljandi to Sredets | 1,108.81 mi (1,784.46 km) |
| Viljandi to Stamboliyski | 1,122.57 mi (1,806.61 km) |
| Viljandi to Stara Zagora | 1,100.89 mi (1,771.72 km) |
| Viljandi to Svilengrad | 1,147.25 mi (1,846.31 km) |
| Viljandi to Svishtov | 1,019.18 mi (1,640.22 km) |
| Viljandi to Targovishte | 1,045.32 mi (1,682.27 km) |
| Viljandi to Teteven | 1,069.04 mi (1,720.45 km) |
| Viljandi to Troyan | 1,070.48 mi (1,722.77 km) |
| Viljandi to Tryavna | 1,070.94 mi (1,723.51 km) |
| Viljandi to Tutrakan | 990.14 mi (1,593.47 km) |
| Viljandi to Varna | 1,051.49 mi (1,692.20 km) |
