Sinan County (simplified Chinese: 思南县; traditional Chinese: 思南縣; pinyin: Sīnán Xiàn) is a county under the administration of the prefecture-level city of Tongren, in the northeast of Guizhou Province, China.

The government is located in Sitang.

Sinan County is divided into 3 subdistricts, 17 towns and 8 ethnic townships:[1]