| Tigard to Olympia (Washington) | 111.92 mi (180.12 km) |
| Tigard to Olympia Heights (Florida) | 2,703.36 mi (4,350.64 km) |
| Tigard to Omaha (Nebraska) | 1,366.91 mi (2,199.83 km) |
| Tigard to On Top of the World Designated Place (Florida) | 2,461.73 mi (3,961.76 km) |
| Tigard to Onalaska (Wisconsin) | 1,545.60 mi (2,487.40 km) |
| Tigard to Oneida (New York) | 2,304.23 mi (3,708.30 km) |
| Tigard to Oneonta (New York) | 2,347.93 mi (3,778.63 km) |
| Tigard to Ontario (California) | 832.85 mi (1,340.34 km) |
| Tigard to Ontario (Oregon) | 300.97 mi (484.36 km) |
| Tigard to Opa-locka (Florida) | 2,699.27 mi (4,344.06 km) |
| Tigard to Opelika (Alabama) | 2,167.86 mi (3,488.83 km) |
| Tigard to Opelousas (Louisiana) | 1,945.64 mi (3,131.21 km) |
| Tigard to Orange (California) | 844.75 mi (1,359.50 km) |
| Tigard to Orange (Texas) | 1,888.86 mi (3,039.82 km) |
| Tigard to Orange City (Florida) | 2,516.31 mi (4,049.60 km) |
