| North Richland Hills to Orbetello | 5,541.48 mi (8,918.15 km) |
| North Richland Hills to Oria | 5,885.68 mi (9,472.08 km) |
| North Richland Hills to Oristano | 5,531.92 mi (8,902.77 km) |
| North Richland Hills to Orta Nova | 5,771.73 mi (9,288.71 km) |
| North Richland Hills to Orte | 5,588.79 mi (8,994.29 km) |
| North Richland Hills to Ortona | 5,675.09 mi (9,133.17 km) |
| North Richland Hills to Orvieto | 5,566.90 mi (8,959.05 km) |
| North Richland Hills to Orzinuovi | 5,371.06 mi (8,643.89 km) |
| North Richland Hills to Osimo | 5,590.55 mi (8,997.12 km) |
| North Richland Hills to Ospitaletto | 5,370.51 mi (8,643.00 km) |
| North Richland Hills to Ostuni | 5,873.29 mi (9,452.15 km) |
| North Richland Hills to Ottaviano | 5,742.15 mi (9,241.10 km) |
| North Richland Hills to Ovada | 5,348.96 mi (8,608.33 km) |
| North Richland Hills to Ozieri | 5,522.86 mi (8,888.18 km) |
| North Richland Hills to Paceco | 5,782.02 mi (9,305.27 km) |
