| South Bend to Oskaloosa (Iowa) | 330.75 mi (532.28 km) |
| South Bend to Oswego (Illinois) | 106.69 mi (171.71 km) |
| South Bend to Oswego (New York) | 511.70 mi (823.51 km) |
| South Bend to Otsego (Minnesota) | 443.95 mi (714.47 km) |
| South Bend to Ottawa (Illinois) | 134.10 mi (215.82 km) |
| South Bend to Ottawa (Kansas) | 520.13 mi (837.07 km) |
| South Bend to Ottumwa (Iowa) | 322.09 mi (518.35 km) |
| South Bend to Overland (Missouri) | 298.62 mi (480.58 km) |
| South Bend to Overland Park (Kansas) | 483.46 mi (778.05 km) |
| South Bend to Overlea (Maryland) | 536.20 mi (862.92 km) |
| South Bend to Oviedo (Florida) | 943.72 mi (1,518.77 km) |
| South Bend to Owasso (Oklahoma) | 633.67 mi (1,019.79 km) |
| South Bend to Owatonna (Minnesota) | 389.76 mi (627.26 km) |
| South Bend to Owensboro (Kentucky) | 274.51 mi (441.78 km) |
| South Bend to Owings Mills (Maryland) | 521.36 mi (839.04 km) |
