| Karlovo to Oegstgeest | 1,150.76 mi (1,851.96 km) |
| Karlovo to Oirschot | 1,097.84 mi (1,766.80 km) |
| Karlovo to Oisterwijk | 1,104.24 mi (1,777.10 km) |
| Karlovo to Oldebroek | 1,106.37 mi (1,780.53 km) |
| Karlovo to Oldenzaal | 1,064.28 mi (1,712.79 km) |
| Karlovo to Ommen | 1,090.06 mi (1,754.28 km) |
| Karlovo to Oosterend | 1,120.23 mi (1,802.84 km) |
| Karlovo to Oosterhout | 1,119.27 mi (1,801.30 km) |
| Karlovo to Oosterwolde | 1,111.84 mi (1,789.33 km) |
| Karlovo to Oostzaan | 1,143.16 mi (1,839.74 km) |
| Karlovo to Opmeer | 1,149.58 mi (1,850.06 km) |
| Karlovo to Oss | 1,097.86 mi (1,766.83 km) |
| Karlovo to Oud-Beijerland | 1,142.10 mi (1,838.03 km) |
| Karlovo to Oudenbosch | 1,130.56 mi (1,819.46 km) |
| Karlovo to Oudewater | 1,130.40 mi (1,819.21 km) |
