| Onex to Nasaud | 868.25 mi (1,397.31 km) |
| Onex to Navodari | 1,098.85 mi (1,768.43 km) |
| Onex to Negresti-Oas | 822.43 mi (1,323.58 km) |
| Onex to Nehoiu | 972.87 mi (1,565.69 km) |
| Onex to Ocna Mures | 846.32 mi (1,362.03 km) |
| Onex to Odobesti | 1,004.26 mi (1,616.20 km) |
| Onex to Odorheiu Secuiesc | 915.25 mi (1,472.96 km) |
| Onex to Oltenita | 1,008.51 mi (1,623.04 km) |
| Onex to Onesti | 985.28 mi (1,585.66 km) |
| Onex to Oradea | 751.91 mi (1,210.08 km) |
| Onex to Orastie | 819.23 mi (1,318.42 km) |
| Onex to Oravita | 756.16 mi (1,216.92 km) |
| Onex to Orsova | 794.80 mi (1,279.10 km) |
| Onex to Otelu Rosu | 782.15 mi (1,258.75 km) |
| Onex to Otopeni | 973.33 mi (1,566.42 km) |
