| Discovery Bay to Olympia Heights (Florida) | 2,540.86 mi (4,089.11 km) |
| Discovery Bay to Omaha (Nebraska) | 1,374.79 mi (2,212.51 km) |
| Discovery Bay to On Top of the World Designated Place (Florida) | 2,326.53 mi (3,744.19 km) |
| Discovery Bay to Onalaska (Wisconsin) | 1,630.06 mi (2,623.33 km) |
| Discovery Bay to Oneida (New York) | 2,409.56 mi (3,877.82 km) |
| Discovery Bay to Oneonta (New York) | 2,445.48 mi (3,935.62 km) |
| Discovery Bay to Ontario (California) | 348.10 mi (560.21 km) |
| Discovery Bay to Ontario (Oregon) | 486.58 mi (783.07 km) |
| Discovery Bay to Opa-locka (Florida) | 2,539.40 mi (4,086.78 km) |
| Discovery Bay to Opelika (Alabama) | 2,061.62 mi (3,317.86 km) |
| Discovery Bay to Opelousas (Louisiana) | 1,753.47 mi (2,821.94 km) |
| Discovery Bay to Orange (California) | 353.60 mi (569.07 km) |
| Discovery Bay to Orange (Texas) | 1,675.10 mi (2,695.82 km) |
| Discovery Bay to Orange City (Florida) | 2,386.01 mi (3,839.92 km) |
| Discovery Bay to Orangeburg (South Carolina) | 2,287.51 mi (3,681.39 km) |
