| Havre de Grace to Oakley (California) | 2,431.24 mi (3,912.70 km) |
| Havre de Grace to Oakton (Virginia) | 78.18 mi (125.82 km) |
| Havre de Grace to Oakville (Missouri) | 765.75 mi (1,232.36 km) |
| Havre de Grace to Oatfield (Oregon) | 2,369.10 mi (3,812.70 km) |
| Havre de Grace to Ocala (Florida) | 794.41 mi (1,278.48 km) |
| Havre de Grace to Ocean Acres (New Jersey) | 98.50 mi (158.52 km) |
| Havre de Grace to Ocean City (New Jersey) | 83.03 mi (133.63 km) |
| Havre de Grace to Ocean Pines (Maryland) | 95.65 mi (153.93 km) |
| Havre de Grace to Ocean Pointe (Hawaii) | 4,876.65 mi (7,848.21 km) |
| Havre de Grace to Ocean Springs (Mississippi) | 953.95 mi (1,535.24 km) |
| Havre de Grace to Oceanside (California) | 2,311.94 mi (3,720.70 km) |
| Havre de Grace to Oceanside (New York) | 150.91 mi (242.87 km) |
| Havre de Grace to Ocoee (Florida) | 818.41 mi (1,317.11 km) |
| Havre de Grace to Oconomowoc (Wisconsin) | 686.83 mi (1,105.35 km) |
| Havre de Grace to Odenton (Maryland) | 45.47 mi (73.18 km) |
