| Port Huron to Oskaloosa (Iowa) | 535.20 mi (861.32 km) |
| Port Huron to Oswego (Illinois) | 314.27 mi (505.77 km) |
| Port Huron to Oswego (New York) | 300.70 mi (483.93 km) |
| Port Huron to Otsego (Minnesota) | 576.03 mi (927.04 km) |
| Port Huron to Ottawa (Illinois) | 345.75 mi (556.44 km) |
| Port Huron to Ottawa (Kansas) | 735.01 mi (1,182.89 km) |
| Port Huron to Ottumwa (Iowa) | 529.69 mi (852.46 km) |
| Port Huron to Overland (Missouri) | 509.05 mi (819.23 km) |
| Port Huron to Overland Park (Kansas) | 698.25 mi (1,123.72 km) |
| Port Huron to Overlea (Maryland) | 396.46 mi (638.05 km) |
| Port Huron to Oviedo (Florida) | 992.15 mi (1,596.71 km) |
| Port Huron to Owasso (Oklahoma) | 847.96 mi (1,364.66 km) |
| Port Huron to Owatonna (Minnesota) | 545.57 mi (878.01 km) |
| Port Huron to Owensboro (Kentucky) | 436.82 mi (703.00 km) |
| Port Huron to Owings Mills (Maryland) | 383.34 mi (616.92 km) |
