| Hammond to Oswego (Illinois) | 43.93 mi (70.70 km) |
| Hammond to Oswego (New York) | 573.27 mi (922.59 km) |
| Hammond to Otsego (Minnesota) | 397.44 mi (639.62 km) |
| Hammond to Ottawa (Illinois) | 71.43 mi (114.95 km) |
| Hammond to Ottawa (Kansas) | 460.37 mi (740.89 km) |
| Hammond to Ottumwa (Iowa) | 258.98 mi (416.79 km) |
| Hammond to Overland (Missouri) | 252.57 mi (406.46 km) |
| Hammond to Overland Park (Kansas) | 423.56 mi (681.66 km) |
| Hammond to Overlea (Maryland) | 596.77 mi (960.42 km) |
| Hammond to Oviedo (Florida) | 962.89 mi (1,549.62 km) |
| Hammond to Owasso (Oklahoma) | 579.50 mi (932.62 km) |
| Hammond to Owatonna (Minnesota) | 337.18 mi (542.63 km) |
| Hammond to Owensboro (Kentucky) | 267.39 mi (430.32 km) |
| Hammond to Owings Mills (Maryland) | 581.88 mi (936.44 km) |
| Hammond to Owosso (Michigan) | 194.31 mi (312.72 km) |
