| Pioltello to Olympia Heights (Florida) | 4,957.33 mi (7,978.06 km) |
| Pioltello to Omaha (Nebraska) | 4,884.51 mi (7,860.86 km) |
| Pioltello to On Top of the World Designated Place (Florida) | 4,888.60 mi (7,867.45 km) |
| Pioltello to Onalaska (Wisconsin) | 4,580.42 mi (7,371.47 km) |
| Pioltello to Oneida (New York) | 3,998.64 mi (6,435.19 km) |
| Pioltello to Oneonta (New York) | 3,998.08 mi (6,434.28 km) |
| Pioltello to Ontario (California) | 6,019.59 mi (9,687.60 km) |
| Pioltello to Ontario (Oregon) | 5,432.28 mi (8,742.42 km) |
| Pioltello to Opa-locka (Florida) | 4,945.30 mi (7,958.70 km) |
| Pioltello to Opelika (Alabama) | 4,859.91 mi (7,821.27 km) |
| Pioltello to Opelousas (Louisiana) | 5,247.59 mi (8,445.18 km) |
| Pioltello to Orange (California) | 6,039.99 mi (9,720.43 km) |
| Pioltello to Orange (Texas) | 5,337.85 mi (8,590.45 km) |
| Pioltello to Orange City (Florida) | 4,851.65 mi (7,807.98 km) |
| Pioltello to Orangeburg (South Carolina) | 4,625.73 mi (7,444.39 km) |
