| Morro Bay to Olympia Heights (Florida) | 2,482.25 mi (3,994.80 km) |
| Morro Bay to Omaha (Nebraska) | 1,398.99 mi (2,251.46 km) |
| Morro Bay to On Top of the World Designated Place (Florida) | 2,280.09 mi (3,669.45 km) |
| Morro Bay to Onalaska (Wisconsin) | 1,672.63 mi (2,691.83 km) |
| Morro Bay to Oneida (New York) | 2,445.85 mi (3,936.21 km) |
| Morro Bay to Oneonta (New York) | 2,478.71 mi (3,989.09 km) |
| Morro Bay to Ontario (California) | 205.75 mi (331.12 km) |
| Morro Bay to Ontario (Oregon) | 632.42 mi (1,017.78 km) |
| Morro Bay to Opa-locka (Florida) | 2,481.76 mi (3,994.00 km) |
| Morro Bay to Opelika (Alabama) | 2,029.25 mi (3,265.77 km) |
| Morro Bay to Opelousas (Louisiana) | 1,694.89 mi (2,727.66 km) |
| Morro Bay to Orange (California) | 203.25 mi (327.11 km) |
| Morro Bay to Orange (Texas) | 1,609.87 mi (2,590.84 km) |
| Morro Bay to Orange City (Florida) | 2,340.61 mi (3,766.85 km) |
| Morro Bay to Orangeburg (South Carolina) | 2,266.69 mi (3,647.89 km) |
