| Smolyan to Oegstgeest | 1,196.99 mi (1,926.37 km) |
| Smolyan to Oirschot | 1,142.80 mi (1,839.16 km) |
| Smolyan to Oisterwijk | 1,149.36 mi (1,849.72 km) |
| Smolyan to Oldebroek | 1,154.89 mi (1,858.61 km) |
| Smolyan to Oldenzaal | 1,113.57 mi (1,792.13 km) |
| Smolyan to Ommen | 1,139.34 mi (1,833.60 km) |
| Smolyan to Oosterend | 1,170.49 mi (1,883.73 km) |
| Smolyan to Oosterhout | 1,164.23 mi (1,873.65 km) |
| Smolyan to Oosterwolde | 1,162.31 mi (1,870.55 km) |
| Smolyan to Oostzaan | 1,190.55 mi (1,916.01 km) |
| Smolyan to Opmeer | 1,197.81 mi (1,927.69 km) |
| Smolyan to Oss | 1,143.89 mi (1,840.92 km) |
| Smolyan to Oud-Beijerland | 1,187.14 mi (1,910.52 km) |
| Smolyan to Oudenbosch | 1,175.02 mi (1,891.01 km) |
| Smolyan to Oudewater | 1,176.54 mi (1,893.45 km) |
