Tongzi (Chinese: 桐梓; pinyin: Tóngzǐ) is a county under the administration of the prefecture-level city of Zunyi, in the north of Guizhou province, China, bordering Chongqing to the north.

The county government is located in the town of Loushanguan.

Tongzi County is divided into 2 subdistricts, 20 towns, 2 townships and 1 ethnic township:[1]