| Houston to Odessa (Texas) | 437.22 mi (703.64 km) |
| Houston to Ogden (Utah) | 1,218.69 mi (1,961.29 km) |
| Houston to Oildale (California) | 1,426.26 mi (2,295.34 km) |
| Houston to Ojus (Florida) | 966.12 mi (1,554.82 km) |
| Houston to Okemos (Michigan) | 1,079.95 mi (1,738.02 km) |
| Houston to Oklahoma City (Oklahoma) | 411.54 mi (662.31 km) |
| Houston to Okmulgee (Oklahoma) | 404.23 mi (650.55 km) |
| Houston to Olathe (Kansas) | 629.39 mi (1,012.91 km) |
| Houston to Old Jamestown (Missouri) | 689.70 mi (1,109.96 km) |
| Houston to Oldsmar (Florida) | 778.07 mi (1,252.18 km) |
| Houston to Olean (New York) | 1,269.03 mi (2,042.30 km) |
| Houston to Olive Branch (Mississippi) | 481.91 mi (775.56 km) |
| Houston to Olivehurst (California) | 1,616.12 mi (2,600.90 km) |
| Houston to Olney (Maryland) | 1,224.00 mi (1,969.83 km) |
| Houston to Olympia (Washington) | 1,890.45 mi (3,042.39 km) |
