| Brussels to Oestrich-Winkel | 170.87 mi (274.98 km) |
| Brussels to Offenburg | 229.50 mi (369.34 km) |
| Brussels to Oftersheim | 213.43 mi (343.48 km) |
| Brussels to Ohrdruf | 278.31 mi (447.90 km) |
| Brussels to Ohringen | 255.18 mi (410.68 km) |
| Brussels to Olbernhau | 392.50 mi (631.67 km) |
| Brussels to Olching | 361.73 mi (582.14 km) |
| Brussels to Oldenburg | 228.36 mi (367.52 km) |
| Brussels to Oldenburg in Holstein | 363.24 mi (584.58 km) |
| Brussels to Olfen | 144.10 mi (231.91 km) |
| Brussels to Olpe | 152.01 mi (244.64 km) |
| Brussels to Olsberg | 182.55 mi (293.79 km) |
| Brussels to Oranienburg | 401.52 mi (646.19 km) |
| Brussels to Ortenberg | 208.97 mi (336.31 km) |
| Brussels to Oschatz | 381.13 mi (613.37 km) |
