| Houston to Nasaud | 5,931.42 mi (9,545.70 km) |
| Houston to Navodari | 6,219.00 mi (10,008.51 km) |
| Houston to Negresti-Oas | 5,870.30 mi (9,447.33 km) |
| Houston to Nehoiu | 6,087.74 mi (9,797.27 km) |
| Houston to Ocna Mures | 5,952.19 mi (9,579.12 km) |
| Houston to Odobesti | 6,095.50 mi (9,809.76 km) |
| Houston to Odorheiu Secuiesc | 6,007.43 mi (9,668.02 km) |
| Houston to Oltenita | 6,158.86 mi (9,911.72 km) |
| Houston to Onesti | 6,061.94 mi (9,755.75 km) |
| Houston to Oradea | 5,851.53 mi (9,417.12 km) |
| Houston to Orastie | 5,952.31 mi (9,579.31 km) |
| Houston to Oravita | 5,931.55 mi (9,545.92 km) |
| Houston to Orsova | 5,972.25 mi (9,611.41 km) |
| Houston to Otelu Rosu | 5,935.64 mi (9,552.48 km) |
| Houston to Otopeni | 6,116.58 mi (9,843.69 km) |
