Daishan (help·info) (Chinese: 岱山县; pinyin: Dàishān Xiàn) is a county under the jurisdiction of Zhoushan, Zhejiang Province. It covers a land area of 326 square kilometres (126 square miles) and has a population of 200,000. The postal code is 316200, and the county seat is located on 88 Renmin Road, Gaoting Town.
The county is located in East China Sea in northeast Zhejiang. It comprises a series of islands with Daishan Island forming the main part of the county. Daishan Island has a fishing port, and shipbuilding and ship refitting facilities. The island has several museums including salt, marine life, typhoon and lifehouse museums.