| Piqua to Orangeburg (South Carolina) | 496.37 mi (798.84 km) |
| Piqua to Orangevale (California) | 1,961.98 mi (3,157.50 km) |
| Piqua to Orchards (Washington) | 1,955.21 mi (3,146.60 km) |
| Piqua to Orcutt (California) | 2,001.93 mi (3,221.80 km) |
| Piqua to Oregon (Ohio) | 112.09 mi (180.40 km) |
| Piqua to Oregon (Wisconsin) | 327.86 mi (527.64 km) |
| Piqua to Oregon City (Oregon) | 1,959.41 mi (3,153.36 km) |
| Piqua to Orem (Utah) | 1,442.57 mi (2,321.59 km) |
| Piqua to Orinda (California) | 2,027.06 mi (3,262.23 km) |
| Piqua to Orland Park (Illinois) | 214.11 mi (344.57 km) |
| Piqua to Orlando (Florida) | 823.29 mi (1,324.96 km) |
| Piqua to Ormond Beach (Florida) | 770.60 mi (1,240.16 km) |
| Piqua to Oro Valley (Arizona) | 1,574.44 mi (2,533.82 km) |
| Piqua to Oroville (California) | 1,966.09 mi (3,164.12 km) |
| Piqua to Oshkosh (Wisconsin) | 347.16 mi (558.70 km) |
