| South Bend to Olympia (Washington) | 1,829.37 mi (2,944.08 km) |
| South Bend to Olympia Heights (Florida) | 1,152.97 mi (1,855.52 km) |
| South Bend to Omaha (Nebraska) | 507.03 mi (815.99 km) |
| South Bend to On Top of the World Designated Place (Florida) | 896.78 mi (1,443.23 km) |
| South Bend to Onalaska (Wisconsin) | 293.27 mi (471.97 km) |
| South Bend to Oneida (New York) | 549.60 mi (884.49 km) |
| South Bend to Oneonta (New York) | 576.72 mi (928.15 km) |
| South Bend to Ontario (California) | 1,777.84 mi (2,861.15 km) |
| South Bend to Ontario (Oregon) | 1,554.77 mi (2,502.16 km) |
| South Bend to Opa-locka (Florida) | 1,142.70 mi (1,839.00 km) |
| South Bend to Opelika (Alabama) | 624.84 mi (1,005.58 km) |
| South Bend to Opelousas (Louisiana) | 835.49 mi (1,344.59 km) |
| South Bend to Orange (California) | 1,796.18 mi (2,890.68 km) |
| South Bend to Orange (Texas) | 900.81 mi (1,449.72 km) |
| South Bend to Orange City (Florida) | 923.65 mi (1,486.47 km) |
