| Cary to Olympia Heights (Florida) | 700.73 mi (1,127.72 km) |
| Cary to Omaha (Nebraska) | 1,003.37 mi (1,614.78 km) |
| Cary to On Top of the World Designated Place (Florida) | 503.53 mi (810.35 km) |
| Cary to Onalaska (Wisconsin) | 861.85 mi (1,387.01 km) |
| Cary to Oneida (New York) | 531.34 mi (855.11 km) |
| Cary to Oneonta (New York) | 502.91 mi (809.35 km) |
| Cary to Ontario (California) | 2,186.61 mi (3,519.01 km) |
| Cary to Ontario (Oregon) | 2,080.68 mi (3,348.53 km) |
| Cary to Opa-locka (Florida) | 688.06 mi (1,107.32 km) |
| Cary to Opelika (Alabama) | 432.10 mi (695.40 km) |
| Cary to Opelousas (Louisiana) | 847.77 mi (1,364.35 km) |
| Cary to Orange (California) | 2,202.66 mi (3,544.85 km) |
| Cary to Orange (Texas) | 949.03 mi (1,527.31 km) |
| Cary to Orange City (Florida) | 494.49 mi (795.80 km) |
| Cary to Orangeburg (South Carolina) | 196.37 mi (316.02 km) |
