| Sliven to Oestrich-Winkel | 1,006.18 mi (1,619.29 km) |
| Sliven to Offenburg | 972.28 mi (1,564.73 km) |
| Sliven to Oftersheim | 965.39 mi (1,553.64 km) |
| Sliven to Ohrdruf | 925.31 mi (1,489.15 km) |
| Sliven to Ohringen | 922.75 mi (1,485.02 km) |
| Sliven to Olbernhau | 824.94 mi (1,327.62 km) |
| Sliven to Olching | 819.77 mi (1,319.29 km) |
| Sliven to Oldenburg | 1,101.85 mi (1,773.26 km) |
| Sliven to Oldenburg in Holstein | 1,065.23 mi (1,714.33 km) |
| Sliven to Olfen | 1,081.52 mi (1,740.54 km) |
| Sliven to Olpe | 1,042.23 mi (1,677.31 km) |
| Sliven to Olsberg | 1,027.88 mi (1,654.22 km) |
| Sliven to Oranienburg | 921.68 mi (1,483.30 km) |
| Sliven to Ortenberg | 974.04 mi (1,567.56 km) |
| Sliven to Oschatz | 859.55 mi (1,383.31 km) |
