Sihong County () is under the administration of Suqian, Jiangsu province, China. It borders the prefecture-level cities of Huai'an to the southeast, Chuzhou (Anhui) to the south, Bengbu (Anhui) to the west, and Suzhou (Anhui) to the northwest.
The area that later became Sihong County probably served as center for the state of Xu during Spring and Autumn period, and harbored its capital city.
At present, Sihong County has 14 towns and 9 townships under its jurisdiction.