| Monserrat to Olympia Heights (Florida) | 4,592.03 mi (7,390.15 km) |
| Monserrat to Omaha (Nebraska) | 4,747.63 mi (7,640.57 km) |
| Monserrat to On Top of the World Designated Place (Florida) | 4,562.55 mi (7,342.72 km) |
| Monserrat to Onalaska (Wisconsin) | 4,442.28 mi (7,149.16 km) |
| Monserrat to Oneida (New York) | 3,775.18 mi (6,075.56 km) |
| Monserrat to Oneonta (New York) | 3,764.79 mi (6,058.84 km) |
| Monserrat to Ontario (California) | 5,964.61 mi (9,599.11 km) |
| Monserrat to Ontario (Oregon) | 5,446.44 mi (8,765.19 km) |
| Monserrat to Opa-locka (Florida) | 4,580.94 mi (7,372.31 km) |
| Monserrat to Opelika (Alabama) | 4,582.70 mi (7,375.14 km) |
| Monserrat to Opelousas (Louisiana) | 4,991.78 mi (8,033.50 km) |
| Monserrat to Orange (California) | 5,984.91 mi (9,631.78 km) |
| Monserrat to Orange (Texas) | 5,089.09 mi (8,190.10 km) |
| Monserrat to Orange City (Florida) | 4,518.43 mi (7,271.71 km) |
| Monserrat to Orangeburg (South Carolina) | 4,330.62 mi (6,969.46 km) |
