| Tomball to Orangeburg (South Carolina) | 896.68 mi (1,443.06 km) |
| Tomball to Orangevale (California) | 1,569.11 mi (2,525.23 km) |
| Tomball to Orchards (Washington) | 1,805.90 mi (2,906.32 km) |
| Tomball to Orcutt (California) | 1,478.65 mi (2,379.65 km) |
| Tomball to Oregon (Ohio) | 1,048.12 mi (1,686.79 km) |
| Tomball to Oregon (Wisconsin) | 950.89 mi (1,530.31 km) |
| Tomball to Oregon City (Oregon) | 1,797.72 mi (2,893.15 km) |
| Tomball to Orem (Utah) | 1,146.30 mi (1,844.79 km) |
| Tomball to Orinda (California) | 1,607.17 mi (2,586.49 km) |
| Tomball to Orland Park (Illinois) | 905.38 mi (1,457.07 km) |
| Tomball to Orlando (Florida) | 867.33 mi (1,395.84 km) |
| Tomball to Ormond Beach (Florida) | 872.50 mi (1,404.15 km) |
| Tomball to Oro Valley (Arizona) | 920.33 mi (1,481.13 km) |
| Tomball to Oroville (California) | 1,601.53 mi (2,577.41 km) |
| Tomball to Oshkosh (Wisconsin) | 1,036.99 mi (1,668.88 km) |
