|Country||People's Republic of China|
|• Total||1,787 km2 (690 sq mi)|
|Time zone||UTC+8 (China Standard)|
Si County or Sixian (simplified Chinese: 泗县; traditional Chinese: 泗縣; pinyin: Sì Xiàn) is a county in the northeast of Anhui Province, China, bordering Jiangsu province to the north and east. It is under the administration of the prefecture-level city of Suzhou City.
In the present, Si County has 12 towns and 3 townships.