| Parker to Olympia (Washington) | 1,046.04 mi (1,683.44 km) |
| Parker to Olympia Heights (Florida) | 1,702.56 mi (2,740.00 km) |
| Parker to Omaha (Nebraska) | 474.54 mi (763.71 km) |
| Parker to On Top of the World Designated Place (Florida) | 1,465.03 mi (2,357.73 km) |
| Parker to Onalaska (Wisconsin) | 761.37 mi (1,225.31 km) |
| Parker to Oneida (New York) | 1,523.45 mi (2,451.76 km) |
| Parker to Oneonta (New York) | 1,554.86 mi (2,502.30 km) |
| Parker to Ontario (California) | 803.30 mi (1,292.78 km) |
| Parker to Ontario (Oregon) | 700.99 mi (1,128.14 km) |
| Parker to Opa-locka (Florida) | 1,698.77 mi (2,733.91 km) |
| Parker to Opelika (Alabama) | 1,178.78 mi (1,897.06 km) |
| Parker to Opelousas (Louisiana) | 947.56 mi (1,524.95 km) |
| Parker to Orange (California) | 822.40 mi (1,323.53 km) |
| Parker to Orange (Texas) | 899.11 mi (1,446.97 km) |
| Parker to Orange City (Florida) | 1,521.18 mi (2,448.10 km) |
