Zhoushan is an urbanized archipelago with the administrative status of a prefecture-level city located in the eastern Chinese province of Zhejiang. It is situated at the southern mouth of Hangzhou Bay, off the mainland city of Ningbo.
The city proper is centered on Dinghai, which is located on Zhoushan Island and currently serves as the Dinghai District. According to the 2020 census, the prefecture had a population of 1,157,817, with 882,932 residents living in the built-up area comprising the urban districts of Dinghai and Putuo.