| Idanha-a-Nova to Oakley (California) | 5,643.56 mi (9,082.43 km) |
| Idanha-a-Nova to Oakton (Virginia) | 3,639.36 mi (5,856.98 km) |
| Idanha-a-Nova to Oakville (Missouri) | 4,275.60 mi (6,880.91 km) |
| Idanha-a-Nova to Oatfield (Oregon) | 5,314.40 mi (8,552.70 km) |
| Idanha-a-Nova to Ocala (Florida) | 4,204.41 mi (6,766.35 km) |
| Idanha-a-Nova to Ocean Acres (New Jersey) | 3,467.84 mi (5,580.95 km) |
| Idanha-a-Nova to Ocean City (New Jersey) | 3,496.60 mi (5,627.24 km) |
| Idanha-a-Nova to Ocean Pines (Maryland) | 3,548.36 mi (5,710.53 km) |
| Idanha-a-Nova to Ocean Pointe (Hawaii) | 7,806.34 mi (12,563.08 km) |
| Idanha-a-Nova to Ocean Springs (Mississippi) | 4,493.95 mi (7,232.32 km) |
| Idanha-a-Nova to Oceanside (California) | 5,696.87 mi (9,168.23 km) |
| Idanha-a-Nova to Oceanside (New York) | 3,412.76 mi (5,492.30 km) |
| Idanha-a-Nova to Ocoee (Florida) | 4,194.70 mi (6,750.72 km) |
| Idanha-a-Nova to Oconomowoc (Wisconsin) | 4,037.23 mi (6,497.29 km) |
| Idanha-a-Nova to Odenton (Maryland) | 3,604.58 mi (5,801.01 km) |
