Hang Prefecture, Hang Zhou, or Hangzhou was a prefecture (zhou) of imperial China from 589 to 1129. It was located in modern northern Zhejiang around the city of Hangzhou, which took its modern name from its role as the usual prefectural seat. The prefecture was called Yuhang Commandery from 607 to 621 and from 742 to 758. Under the names Western Prefecture (Xizhou) and Qiantang Prefecture, Hang Prefecture served as the capital of the Wuyue Kingdom from its founding in 907 to its abolition in 978.

Hang Prefecture sat at the head of the Hangzhou Bay, which opens to the East China Sea. It was also the southern terminus of the Grand Canal and the eastern terminus of the Qiantang River. During the Northern Song (960–1127) it was the capital of Liangzhe Circuit. In 1129 it became Lin'an Prefecture, which would become the capital of the Southern Song (1127–1279) in 1138.

For most of its history, Hang Prefecture administered the following 7–9 counties (縣), some of whose names changed frequently:

In 587, the southern Chen dynasty (557–589) created Qiantang Commandery (錢唐郡), which administered four counties. When the northern Sui dynasty (581–618) conquered the Chen dynasty in 589, Qiantang Commandery was renamed to Hang Prefecture.

In 606, the City Walls were built.

In 607, Emperor Yang of Sui renamed hundreds of prefectures. Hang Prefecture was renamed to Yuhang Commandery.

In 609, the Grand Canal was completed.

During the transition from Sui to Tang, the warlord Shen Faxing first held Yuhang Commandery in the confusion following the assassination of Emperor Yang in 618. In 620, he was defeated by the warlord Li Zitong, who took over his territory.