| Castelo Branco to Oakley (California) | 5,638.05 mi (9,073.56 km) |
| Castelo Branco to Oakton (Virginia) | 3,629.04 mi (5,840.38 km) |
| Castelo Branco to Oakville (Missouri) | 4,266.38 mi (6,866.08 km) |
| Castelo Branco to Oatfield (Oregon) | 5,310.42 mi (8,546.29 km) |
| Castelo Branco to Ocala (Florida) | 4,192.56 mi (6,747.27 km) |
| Castelo Branco to Ocean Acres (New Jersey) | 3,457.48 mi (5,564.27 km) |
| Castelo Branco to Ocean City (New Jersey) | 3,486.15 mi (5,610.42 km) |
| Castelo Branco to Ocean Pines (Maryland) | 3,537.74 mi (5,693.44 km) |
| Castelo Branco to Ocean Pointe (Hawaii) | 7,805.32 mi (12,561.46 km) |
| Castelo Branco to Ocean Springs (Mississippi) | 4,482.98 mi (7,214.65 km) |
| Castelo Branco to Oceanside (California) | 5,689.86 mi (9,156.94 km) |
| Castelo Branco to Oceanside (New York) | 3,402.57 mi (5,475.91 km) |
| Castelo Branco to Ocoee (Florida) | 4,182.68 mi (6,731.37 km) |
| Castelo Branco to Oconomowoc (Wisconsin) | 4,028.92 mi (6,483.91 km) |
| Castelo Branco to Odenton (Maryland) | 3,594.25 mi (5,784.39 km) |
