| Valley Center to Olympia (Washington) | 1,002.62 mi (1,613.57 km) |
| Valley Center to Olympia Heights (Florida) | 2,254.06 mi (3,627.55 km) |
| Valley Center to Omaha (Nebraska) | 1,275.02 mi (2,051.95 km) |
| Valley Center to On Top of the World Designated Place (Florida) | 2,063.38 mi (3,320.68 km) |
| Valley Center to Onalaska (Wisconsin) | 1,567.48 mi (2,522.62 km) |
| Valley Center to Oneida (New York) | 2,321.48 mi (3,736.06 km) |
| Valley Center to Oneonta (New York) | 2,349.97 mi (3,781.90 km) |
| Valley Center to Ontario (California) | 65.25 mi (105.01 km) |
| Valley Center to Ontario (Oregon) | 745.72 mi (1,200.12 km) |
| Valley Center to Opa-locka (Florida) | 2,254.35 mi (3,628.03 km) |
| Valley Center to Opelika (Alabama) | 1,827.84 mi (2,941.62 km) |
| Valley Center to Opelousas (Louisiana) | 1,471.31 mi (2,367.85 km) |
| Valley Center to Orange (California) | 60.92 mi (98.04 km) |
| Valley Center to Orange (Texas) | 1,381.23 mi (2,222.87 km) |
| Valley Center to Orange City (Florida) | 2,124.52 mi (3,419.08 km) |
