| Rio Grande City to Odenton (Maryland) | 1,549.62 mi (2,493.87 km) |
| Rio Grande City to Odessa (Texas) | 435.34 mi (700.61 km) |
| Rio Grande City to Ogden (Utah) | 1,270.34 mi (2,044.41 km) |
| Rio Grande City to Oildale (California) | 1,347.61 mi (2,168.77 km) |
| Rio Grande City to Ojus (Florida) | 1,156.55 mi (1,861.29 km) |
| Rio Grande City to Okemos (Michigan) | 1,390.11 mi (2,237.17 km) |
| Rio Grande City to Oklahoma City (Oklahoma) | 632.58 mi (1,018.05 km) |
| Rio Grande City to Okmulgee (Oklahoma) | 659.24 mi (1,060.94 km) |
| Rio Grande City to Olathe (Kansas) | 894.40 mi (1,439.39 km) |
| Rio Grande City to Old Jamestown (Missouri) | 992.75 mi (1,597.67 km) |
| Rio Grande City to Oldsmar (Florida) | 998.36 mi (1,606.71 km) |
| Rio Grande City to Olean (New York) | 1,583.83 mi (2,548.93 km) |
| Rio Grande City to Olive Branch (Mississippi) | 796.66 mi (1,282.09 km) |
| Rio Grande City to Olivehurst (California) | 1,578.98 mi (2,541.12 km) |
| Rio Grande City to Olney (Maryland) | 1,534.39 mi (2,469.37 km) |
