| Northampton to Olympia Heights (Florida) | 4,396.38 mi (7,075.28 km) |
| Northampton to Omaha (Nebraska) | 4,236.74 mi (6,818.37 km) |
| Northampton to On Top of the World Designated Place (Florida) | 4,305.60 mi (6,929.20 km) |
| Northampton to Onalaska (Wisconsin) | 3,933.84 mi (6,330.91 km) |
| Northampton to Oneida (New York) | 3,378.43 mi (5,437.06 km) |
| Northampton to Oneonta (New York) | 3,381.51 mi (5,442.02 km) |
| Northampton to Ontario (California) | 5,363.27 mi (8,631.35 km) |
| Northampton to Ontario (Oregon) | 4,778.55 mi (7,690.33 km) |
| Northampton to Opa-locka (Florida) | 4,383.89 mi (7,055.19 km) |
| Northampton to Opelika (Alabama) | 4,253.68 mi (6,845.64 km) |
| Northampton to Opelousas (Louisiana) | 4,629.98 mi (7,451.23 km) |
| Northampton to Orange (California) | 5,383.67 mi (8,664.17 km) |
| Northampton to Orange (Texas) | 4,717.11 mi (7,591.46 km) |
| Northampton to Orange City (Florida) | 4,272.93 mi (6,876.61 km) |
| Northampton to Orangeburg (South Carolina) | 4,029.66 mi (6,485.12 km) |
