| Fort Madison to Orangevale (California) | 1,586.91 mi (2,553.88 km) |
| Fort Madison to Orchards (Washington) | 1,599.32 mi (2,573.86 km) |
| Fort Madison to Orcutt (California) | 1,629.17 mi (2,621.89 km) |
| Fort Madison to Oregon (Ohio) | 418.03 mi (672.76 km) |
| Fort Madison to Oregon (Wisconsin) | 188.59 mi (303.51 km) |
| Fort Madison to Oregon City (Oregon) | 1,601.89 mi (2,577.99 km) |
| Fort Madison to Orem (Utah) | 1,067.58 mi (1,718.11 km) |
| Fort Madison to Orinda (California) | 1,651.77 mi (2,658.26 km) |
| Fort Madison to Orland Park (Illinois) | 193.98 mi (312.18 km) |
| Fort Madison to Orlando (Florida) | 1,012.67 mi (1,629.74 km) |
| Fort Madison to Ormond Beach (Florida) | 972.53 mi (1,565.14 km) |
| Fort Madison to Oro Valley (Arizona) | 1,224.35 mi (1,970.40 km) |
| Fort Madison to Oroville (California) | 1,591.71 mi (2,561.62 km) |
| Fort Madison to Oshkosh (Wisconsin) | 274.82 mi (442.29 km) |
| Fort Madison to Oskaloosa (Iowa) | 81.73 mi (131.53 km) |
