| Portage to Olympia (Washington) | 1,846.73 mi (2,972.02 km) |
| Portage to Olympia Heights (Florida) | 1,176.86 mi (1,893.97 km) |
| Portage to Omaha (Nebraska) | 542.99 mi (873.85 km) |
| Portage to On Top of the World Designated Place (Florida) | 923.33 mi (1,485.96 km) |
| Portage to Onalaska (Wisconsin) | 306.60 mi (493.42 km) |
| Portage to Oneida (New York) | 507.96 mi (817.48 km) |
| Portage to Oneonta (New York) | 537.52 mi (865.06 km) |
| Portage to Ontario (California) | 1,816.99 mi (2,924.16 km) |
| Portage to Ontario (Oregon) | 1,578.47 mi (2,540.29 km) |
| Portage to Opa-locka (Florida) | 1,166.27 mi (1,876.94 km) |
| Portage to Opelika (Alabama) | 659.17 mi (1,060.83 km) |
| Portage to Opelousas (Louisiana) | 883.11 mi (1,421.23 km) |
| Portage to Orange (California) | 1,835.49 mi (2,953.94 km) |
| Portage to Orange (Texas) | 949.69 mi (1,528.38 km) |
| Portage to Orange City (Florida) | 947.54 mi (1,524.92 km) |
