| Sliven to Orzesze | 629.07 mi (1,012.40 km) |
| Sliven to Osowa | 886.22 mi (1,426.24 km) |
| Sliven to Ostroda | 814.91 mi (1,311.47 km) |
| Sliven to Ostroleka | 750.24 mi (1,207.39 km) |
| Sliven to Ostrow Mazowiecka | 728.36 mi (1,172.18 km) |
| Sliven to Ostrow Wielkopolski | 736.35 mi (1,185.04 km) |
| Sliven to Ostrowiec Swietokrzyski | 615.56 mi (990.65 km) |
| Sliven to Ostrzeszow | 720.41 mi (1,159.39 km) |
| Sliven to Oswiecim | 610.31 mi (982.19 km) |
| Sliven to Otwock | 693.09 mi (1,115.42 km) |
| Sliven to Ozarow Mazowiecki | 707.10 mi (1,137.96 km) |
| Sliven to Ozimek | 672.12 mi (1,081.67 km) |
| Sliven to Ozorkow | 720.61 mi (1,159.72 km) |
| Sliven to Pabianice | 699.55 mi (1,125.81 km) |
| Sliven to Parczew | 639.28 mi (1,028.82 km) |
