| Mason City to Odessa (Texas) | 924.63 mi (1,488.05 km) |
| Mason City to Ogden (Utah) | 967.87 mi (1,557.64 km) |
| Mason City to Oildale (California) | 1,473.34 mi (2,371.12 km) |
| Mason City to Ojus (Florida) | 1,396.71 mi (2,247.78 km) |
| Mason City to Okemos (Michigan) | 445.35 mi (716.73 km) |
| Mason City to Oklahoma City (Oklahoma) | 578.44 mi (930.91 km) |
| Mason City to Okmulgee (Oklahoma) | 541.70 mi (871.78 km) |
| Mason City to Olathe (Kansas) | 306.56 mi (493.36 km) |
| Mason City to Old Jamestown (Missouri) | 334.25 mi (537.92 km) |
| Mason City to Oldsmar (Florida) | 1,196.95 mi (1,926.30 km) |
| Mason City to Olean (New York) | 753.51 mi (1,212.65 km) |
| Mason City to Olive Branch (Mississippi) | 593.49 mi (955.12 km) |
| Mason City to Olivehurst (California) | 1,495.17 mi (2,406.24 km) |
| Mason City to Olney (Maryland) | 881.84 mi (1,419.18 km) |
| Mason City to Olympia (Washington) | 1,464.00 mi (2,356.09 km) |
