Tonghai County (Chinese: 通海县; pinyin: Tōnghǎi Xiàn) is located in Yuxi Prefecture-level City, Yunnan Province, China.

Tonghai County occupies the fertile valley of Qilu Lake, surrounded on all sides by mountains.

The county's southernmost part, including the Dagao Dai and Yi Ethnic Township and Lishan Yi Ethnic Township, is separated from the rest of the county by mountains; it is outside of the Qilu Lake basin, and is drained into the Qu River instead.

Centers of Hui culture include Dahui and Xiaohui villages in Hexi Township, as well as Nagu Town, with its Najiaying Mosque.

[3] Bus routes: Railway: This Yunnan location article is a stub.