| Gretna to Orangevale (California) | 1,868.94 mi (3,007.77 km) |
| Gretna to Orchards (Washington) | 2,060.23 mi (3,315.62 km) |
| Gretna to Orcutt (California) | 1,797.61 mi (2,892.97 km) |
| Gretna to Oregon (Ohio) | 891.41 mi (1,434.58 km) |
| Gretna to Oregon (Wisconsin) | 900.01 mi (1,448.42 km) |
| Gretna to Oregon City (Oregon) | 2,054.72 mi (3,306.76 km) |
| Gretna to Orem (Utah) | 1,412.92 mi (2,273.88 km) |
| Gretna to Orinda (California) | 1,912.37 mi (3,077.67 km) |
| Gretna to Orland Park (Illinois) | 817.40 mi (1,315.48 km) |
| Gretna to Orlando (Florida) | 534.73 mi (860.56 km) |
| Gretna to Ormond Beach (Florida) | 539.19 mi (867.74 km) |
| Gretna to Oro Valley (Arizona) | 1,247.19 mi (2,007.15 km) |
| Gretna to Oroville (California) | 1,896.80 mi (3,052.61 km) |
| Gretna to Oshkosh (Wisconsin) | 978.50 mi (1,574.74 km) |
| Gretna to Oskaloosa (Iowa) | 799.65 mi (1,286.91 km) |
