| Sintra to Orangevale (California) | 5,560.45 mi (8,948.68 km) |
| Sintra to Orchards (Washington) | 5,281.75 mi (8,500.15 km) |
| Sintra to Orcutt (California) | 5,707.39 mi (9,185.16 km) |
| Sintra to Oregon (Ohio) | 3,785.88 mi (6,092.79 km) |
| Sintra to Oregon (Wisconsin) | 4,026.50 mi (6,480.02 km) |
| Sintra to Oregon City (Oregon) | 5,300.18 mi (8,529.81 km) |
| Sintra to Orem (Utah) | 5,101.03 mi (8,209.31 km) |
| Sintra to Orinda (California) | 5,636.50 mi (9,071.08 km) |
| Sintra to Orland Park (Illinois) | 3,995.29 mi (6,429.80 km) |
| Sintra to Orlando (Florida) | 4,094.94 mi (6,590.16 km) |
| Sintra to Ormond Beach (Florida) | 4,054.07 mi (6,524.39 km) |
| Sintra to Oro Valley (Arizona) | 5,405.98 mi (8,700.08 km) |
| Sintra to Oroville (California) | 5,535.76 mi (8,908.95 km) |
| Sintra to Oshkosh (Wisconsin) | 3,956.84 mi (6,367.92 km) |
| Sintra to Oskaloosa (Iowa) | 4,226.07 mi (6,801.21 km) |
