| Gretna to Oakley (California) | 1,887.22 mi (3,037.19 km) |
| Gretna to Oakton (Virginia) | 953.88 mi (1,535.12 km) |
| Gretna to Oakville (Missouri) | 590.10 mi (949.68 km) |
| Gretna to Oatfield (Oregon) | 2,056.47 mi (3,309.57 km) |
| Gretna to Ocala (Florida) | 477.48 mi (768.43 km) |
| Gretna to Ocean Acres (New Jersey) | 1,120.36 mi (1,803.04 km) |
| Gretna to Ocean City (New Jersey) | 1,088.40 mi (1,751.62 km) |
| Gretna to Ocean Pines (Maryland) | 1,031.80 mi (1,660.52 km) |
| Gretna to Ocean Pointe (Hawaii) | 4,218.15 mi (6,788.45 km) |
| Gretna to Ocean Springs (Mississippi) | 83.06 mi (133.67 km) |
| Gretna to Oceanside (California) | 1,616.20 mi (2,601.03 km) |
| Gretna to Oceanside (New York) | 1,182.40 mi (1,902.88 km) |
| Gretna to Ocoee (Florida) | 521.57 mi (839.39 km) |
| Gretna to Oconomowoc (Wisconsin) | 915.35 mi (1,473.11 km) |
| Gretna to Odenton (Maryland) | 987.46 mi (1,589.16 km) |
