Huai'an is a prefecture-level city in Jiangsu Province in eastern China. It was formerly known as Huaiyin. The city lies in the eastern part of the country, within the Jiangsu region.
As of 2020, the built-up area of Huai'an's three central urban districts had a population of 2,544,767. The prefecture-level city as a whole had 4,556,230 inhabitants in the same year.