| Mason City to Oakley (California) | 1,529.38 mi (2,461.30 km) |
| Mason City to Oakton (Virginia) | 877.82 mi (1,412.71 km) |
| Mason City to Oakville (Missouri) | 357.96 mi (576.08 km) |
| Mason City to Oatfield (Oregon) | 1,454.22 mi (2,340.34 km) |
| Mason City to Ocala (Florida) | 1,142.93 mi (1,839.36 km) |
| Mason City to Ocean Acres (New Jersey) | 1,005.33 mi (1,617.92 km) |
| Mason City to Ocean City (New Jersey) | 1,000.83 mi (1,610.68 km) |
| Mason City to Ocean Pines (Maryland) | 997.88 mi (1,605.94 km) |
| Mason City to Ocean Pointe (Hawaii) | 3,971.15 mi (6,390.94 km) |
| Mason City to Ocean Springs (Mississippi) | 913.17 mi (1,469.61 km) |
| Mason City to Oceanside (California) | 1,470.49 mi (2,366.52 km) |
| Mason City to Oceanside (New York) | 1,018.70 mi (1,639.44 km) |
| Mason City to Ocoee (Florida) | 1,197.33 mi (1,926.92 km) |
| Mason City to Oconomowoc (Wisconsin) | 237.26 mi (381.83 km) |
| Mason City to Odenton (Maryland) | 902.62 mi (1,452.63 km) |
