Zhoushan is a prefecture-level city located in the eastern Chinese province of Zhejiang. It is characterized as an urbanized archipelago situated at the southern mouth of Hangzhou Bay, off the mainland city of Ningbo.
The city's administrative center is Dinghai, which is located on Zhoushan Island and currently functions as the Dinghai District. The primary built-up area of the prefecture consists of two urban districts: Dinghai and Putuo.
According to the 2020 census, the total population of Zhoushan Prefecture was 1,157,817. Of this population, 882,932 residents live within the built-up area comprising the two urban districts.