| Waltham to Olympia (Washington) | 2,509.94 mi (4,039.36 km) |
| Waltham to Olympia Heights (Florida) | 1,261.83 mi (2,030.71 km) |
| Waltham to Omaha (Nebraska) | 1,275.24 mi (2,052.30 km) |
| Waltham to On Top of the World Designated Place (Florida) | 1,105.02 mi (1,778.35 km) |
| Waltham to Onalaska (Wisconsin) | 1,009.43 mi (1,624.52 km) |
| Waltham to Oneida (New York) | 229.27 mi (368.97 km) |
| Waltham to Oneonta (New York) | 195.09 mi (313.97 km) |
| Waltham to Ontario (California) | 2,549.34 mi (4,102.77 km) |
| Waltham to Ontario (Oregon) | 2,276.17 mi (3,663.14 km) |
| Waltham to Opa-locka (Florida) | 1,248.62 mi (2,009.46 km) |
| Waltham to Opelika (Alabama) | 1,022.99 mi (1,646.35 km) |
| Waltham to Opelousas (Louisiana) | 1,412.49 mi (2,273.18 km) |
| Waltham to Orange (California) | 2,567.77 mi (4,132.42 km) |
| Waltham to Orange (Texas) | 1,506.48 mi (2,424.44 km) |
| Waltham to Orange City (Florida) | 1,085.43 mi (1,746.82 km) |
