| Zhangzi County | |
| Other Name: | Changtze |
| Postal Code Type: | Postal code |
| Settlement Type: | County |
| Image Map1: | Location of Changzhi Prefecture within Shanxi (China).png |
| Subdivision Type: | Country |
| Subdivision Name: | People's Republic of China |
| Subdivision Type1: | Province |
| Subdivision Name1: | Shanxi |
| Subdivision Type2: | Prefecture-level city |
| Subdivision Name2: | Changzhi |
| Population: | 298,690 |
| Population As Of: | 2020[1] |
| Population Density Km2: | auto |
| Timezone: | China Standard |
| Utc Offset: | +8 |
| Website: | Zhangzi.gov.cn |
Zhangzi County is a county in the southeast of Shanxi province, China. It is under the administration of the prefecture-level city of Changzhi.