| Walnut Creek to Odenton (Maryland) | 2,428.06 mi (3,907.58 km) |
| Walnut Creek to Odessa (Texas) | 1,188.33 mi (1,912.44 km) |
| Walnut Creek to Ogden (Utah) | 583.13 mi (938.45 km) |
| Walnut Creek to Oildale (California) | 238.75 mi (384.23 km) |
| Walnut Creek to Ojus (Florida) | 2,566.46 mi (4,130.31 km) |
| Walnut Creek to Okemos (Michigan) | 1,993.33 mi (3,207.96 km) |
| Walnut Creek to Oklahoma City (Oklahoma) | 1,365.34 mi (2,197.31 km) |
| Walnut Creek to Okmulgee (Oklahoma) | 1,445.01 mi (2,325.51 km) |
| Walnut Creek to Olathe (Kansas) | 1,470.14 mi (2,365.97 km) |
| Walnut Creek to Old Jamestown (Missouri) | 1,712.71 mi (2,756.34 km) |
| Walnut Creek to Oldsmar (Florida) | 2,361.99 mi (3,801.25 km) |
| Walnut Creek to Olean (New York) | 2,301.20 mi (3,703.43 km) |
| Walnut Creek to Olive Branch (Mississippi) | 1,792.19 mi (2,884.25 km) |
| Walnut Creek to Olivehurst (California) | 85.43 mi (137.48 km) |
| Walnut Creek to Olney (Maryland) | 2,407.08 mi (3,873.82 km) |
