| Viseu to Olympia Heights (Florida) | 4,194.73 mi (6,750.76 km) |
| Viseu to Omaha (Nebraska) | 4,378.03 mi (7,045.76 km) |
| Viseu to On Top of the World Designated Place (Florida) | 4,165.96 mi (6,704.47 km) |
| Viseu to Onalaska (Wisconsin) | 4,073.77 mi (6,556.10 km) |
| Viseu to Oneida (New York) | 3,391.66 mi (5,458.35 km) |
| Viseu to Oneonta (New York) | 3,379.61 mi (5,438.95 km) |
| Viseu to Ontario (California) | 5,610.32 mi (9,028.94 km) |
| Viseu to Ontario (Oregon) | 5,116.37 mi (8,234.00 km) |
| Viseu to Opa-locka (Florida) | 4,183.63 mi (6,732.90 km) |
| Viseu to Opelika (Alabama) | 4,189.68 mi (6,742.64 km) |
| Viseu to Opelousas (Louisiana) | 4,600.46 mi (7,403.73 km) |
| Viseu to Orange (California) | 5,630.50 mi (9,061.41 km) |
| Viseu to Orange (Texas) | 4,698.44 mi (7,561.42 km) |
| Viseu to Orange City (Florida) | 4,121.57 mi (6,633.03 km) |
| Viseu to Orangeburg (South Carolina) | 3,936.27 mi (6,334.81 km) |
