| Zagarolo to Olympia Heights (Florida) | 5,208.51 mi (8,382.29 km) |
| Zagarolo to Omaha (Nebraska) | 5,182.97 mi (8,341.19 km) |
| Zagarolo to On Top of the World Designated Place (Florida) | 5,151.17 mi (8,290.01 km) |
| Zagarolo to Onalaska (Wisconsin) | 4,878.25 mi (7,850.78 km) |
| Zagarolo to Oneida (New York) | 4,282.25 mi (6,891.62 km) |
| Zagarolo to Oneonta (New York) | 4,279.82 mi (6,887.71 km) |
| Zagarolo to Ontario (California) | 6,325.88 mi (10,180.52 km) |
| Zagarolo to Ontario (Oregon) | 5,740.08 mi (9,237.76 km) |
| Zagarolo to Opa-locka (Florida) | 5,196.75 mi (8,363.36 km) |
| Zagarolo to Opelika (Alabama) | 5,134.61 mi (8,263.35 km) |
| Zagarolo to Opelousas (Louisiana) | 5,527.79 mi (8,896.11 km) |
| Zagarolo to Orange (California) | 6,346.28 mi (10,213.35 km) |
| Zagarolo to Orange (Texas) | 5,619.67 mi (9,043.98 km) |
| Zagarolo to Orange City (Florida) | 5,112.14 mi (8,227.20 km) |
| Zagarolo to Orangeburg (South Carolina) | 4,895.65 mi (7,878.78 km) |
