| Chelmsford to Oswego (Illinois) | 3,999.32 mi (6,436.28 km) |
| Chelmsford to Oswego (New York) | 3,462.65 mi (5,572.60 km) |
| Chelmsford to Otsego (Minnesota) | 4,023.10 mi (6,474.56 km) |
| Chelmsford to Ottawa (Illinois) | 4,033.27 mi (6,490.92 km) |
| Chelmsford to Ottawa (Kansas) | 4,408.79 mi (7,095.26 km) |
| Chelmsford to Ottumwa (Iowa) | 4,183.69 mi (6,733.00 km) |
| Chelmsford to Overland (Missouri) | 4,219.80 mi (6,791.11 km) |
| Chelmsford to Overland Park (Kansas) | 4,372.99 mi (7,037.65 km) |
| Chelmsford to Overlea (Maryland) | 3,642.72 mi (5,862.39 km) |
| Chelmsford to Oviedo (Florida) | 4,347.13 mi (6,996.03 km) |
| Chelmsford to Owasso (Oklahoma) | 4,546.98 mi (7,317.66 km) |
| Chelmsford to Owatonna (Minnesota) | 4,065.21 mi (6,542.33 km) |
| Chelmsford to Owensboro (Kentucky) | 4,139.82 mi (6,662.40 km) |
| Chelmsford to Owings Mills (Maryland) | 3,651.67 mi (5,876.80 km) |
| Chelmsford to Owosso (Michigan) | 3,780.73 mi (6,084.50 km) |
