| Monserrato to Olympia Heights (Florida) | 5,091.46 mi (8,193.91 km) |
| Monserrato to Omaha (Nebraska) | 5,158.18 mi (8,301.28 km) |
| Monserrato to On Top of the World Designated Place (Florida) | 5,050.32 mi (8,127.70 km) |
| Monserrato to Onalaska (Wisconsin) | 4,852.25 mi (7,808.95 km) |
| Monserrato to Oneida (New York) | 4,221.65 mi (6,794.10 km) |
| Monserrato to Oneonta (New York) | 4,215.38 mi (6,784.00 km) |
| Monserrato to Ontario (California) | 6,336.55 mi (10,197.68 km) |
| Monserrato to Ontario (Oregon) | 5,776.29 mi (9,296.04 km) |
| Monserrato to Opa-locka (Florida) | 5,080.09 mi (8,175.61 km) |
| Monserrato to Opelika (Alabama) | 5,053.64 mi (8,133.05 km) |
| Monserrato to Opelousas (Louisiana) | 5,455.85 mi (8,780.34 km) |
| Monserrato to Orange (California) | 6,356.97 mi (10,230.55 km) |
| Monserrato to Orange (Texas) | 5,550.69 mi (8,932.98 km) |
| Monserrato to Orange City (Florida) | 5,008.34 mi (8,060.14 km) |
| Monserrato to Orangeburg (South Carolina) | 4,807.28 mi (7,736.57 km) |
