| Houston to Orangevale (California) | 1,591.63 mi (2,561.48 km) |
| Houston to Orchards (Washington) | 1,830.71 mi (2,946.25 km) |
| Houston to Orcutt (California) | 1,498.87 mi (2,412.20 km) |
| Houston to Oregon (Ohio) | 1,057.07 mi (1,701.19 km) |
| Houston to Oregon (Wisconsin) | 966.59 mi (1,555.57 km) |
| Houston to Oregon City (Oregon) | 1,822.45 mi (2,932.95 km) |
| Houston to Orem (Utah) | 1,170.92 mi (1,884.42 km) |
| Houston to Orinda (California) | 1,629.17 mi (2,621.90 km) |
| Houston to Orland Park (Illinois) | 918.59 mi (1,478.32 km) |
| Houston to Orlando (Florida) | 852.32 mi (1,371.68 km) |
| Houston to Ormond Beach (Florida) | 858.92 mi (1,382.30 km) |
| Houston to Oro Valley (Arizona) | 939.08 mi (1,511.31 km) |
| Houston to Oroville (California) | 1,624.41 mi (2,614.24 km) |
| Houston to Oshkosh (Wisconsin) | 1,052.52 mi (1,693.87 km) |
| Houston to Oskaloosa (Iowa) | 809.75 mi (1,303.17 km) |
