| Castelo Branco to Odessa (Texas) | 5,082.13 mi (8,178.89 km) |
| Castelo Branco to Ogden (Utah) | 5,104.46 mi (8,214.84 km) |
| Castelo Branco to Oildale (California) | 5,656.32 mi (9,102.97 km) |
| Castelo Branco to Ojus (Florida) | 4,208.89 mi (6,773.56 km) |
| Castelo Branco to Okemos (Michigan) | 3,855.35 mi (6,204.58 km) |
| Castelo Branco to Oklahoma City (Oklahoma) | 4,712.02 mi (7,583.27 km) |
| Castelo Branco to Okmulgee (Oklahoma) | 4,636.06 mi (7,461.02 km) |
| Castelo Branco to Olathe (Kansas) | 4,459.12 mi (7,176.26 km) |
| Castelo Branco to Old Jamestown (Missouri) | 4,251.21 mi (6,841.66 km) |
| Castelo Branco to Oldsmar (Florida) | 4,260.66 mi (6,856.86 km) |
| Castelo Branco to Olean (New York) | 3,594.25 mi (5,784.39 km) |
| Castelo Branco to Olive Branch (Mississippi) | 4,367.24 mi (7,028.39 km) |
| Castelo Branco to Olivehurst (California) | 5,579.82 mi (8,979.85 km) |
| Castelo Branco to Olney (Maryland) | 3,610.40 mi (5,810.37 km) |
| Castelo Branco to Olympia (Washington) | 5,242.02 mi (8,436.22 km) |
