| Locality | Postal Code |
|---|---|
| Neatari (石岡市) | 315-0029 |
| Negoya (石岡市) | 315-0132 |
| Noda (石岡市) | 315-0118 |
| Obata (石岡市) | 315-0155 |
| Ogura (石岡市) | 315-0165 |
| Omasu (石岡市) | 315-0101 |
| Omi (石岡市) | 315-0104 |
| Onogoe (石岡市) | 315-0144 |
| Osuna (石岡市) | 315-0009 |
| Ota (石岡市) | 315-0102 |
| Others (石岡市) | 315-0000 |
| Otsuka (石岡市) | 315-0105 |
| Oyamada (石岡市) | 315-0166 |
| Oyatsu (石岡市) | 315-0036 |
| Ryumei (石岡市) | 315-0167 |
| Sakaematsu (石岡市) | 315-0019 |
| Saku (石岡市) | 315-0117 |
| Shibama (石岡市) | 315-0124 |
| Shibauchi (石岡市) | 315-0143 |
| Shimoaoyagi (石岡市) | 315-0153 |
| Shimobayashi (石岡市) | 315-0131 |
| Shobuzawa (石岡市) | 315-0146 |
| Shojouchi (石岡市) | 315-0011 |
| Someya (石岡市) | 315-0007 |
| Sosha (石岡市) | 315-0016 |
| Sugama (石岡市) | 315-0151 |