| Locality | Post Code |
|---|---|
| Sakuranomori (つくば市) | 305-0019 |
| Sasagi (つくば市) | 305-0043 |
| Sengen (つくば市) | 305-0047 |
| Shibasaki (つくば市) | 305-0004 |
| Shima (つくば市) | 305-0833 |
| Shimana (つくば市) | 300-2655 |
| Shimobeppu (つくば市) | 300-2666 |
| Shimohara (つくば市) | 305-0063 |
| Shimohiratsuka (つくば市) | 305-0813 |
| Shimohiroka (つくば市) | 305-0042 |
| Shimoiwasaki (つくば市) | 300-1273 |
| Shimokawarazaki (つくば市) | 300-2662 |
| Shimokayamaru (つくば市) | 305-0872 |
| Shimooshima (つくば市) | 300-4222 |
| Shimoyokoba (つくば市) | 305-0075 |
| Shinozaki (つくば市) | 300-3264 |
| Shiroyama (つくば市) | 300-1251 |
| Shoei (つくば市) | 305-0014 |