Kunqu also known as Kunju (昆剧), Kun opera or Kunqu Opera, is one of the oldest extant forms of Chinese opera.

It evolved from the Kunshan melody, and dominated Chinese theatre from the 16th to the 18th centuries. The style originated in the Wu cultural area. It is listed as one of the Masterpieces of the Oral and Intangible Heritage of Humanity by UNESCO since 2001

Kunqu (Kunshan play) was developed during the late Yuan Dynasty (14th),by Gu Jian (顾坚) of Qiandeng town in Kunshan[2], and due to its influence on other Chinese theatre forms, it is known as the "teacher" or "mother" of a hundred operas, including Jingju (Peking Opera). Its emergence ushered in the second Golden Era of Chinese drama. However, by the early twentieth century, it had nearly disappeared, which was only exacerbated by deliberate attempts to suppress it during the Cultural Revolution. Today, Kunqu is performed professionally in seven Mainland Chinese cities: Beijing (Northern Kunqu Theatre), Shanghai (Shanghai Kunqu Theatre), Suzhou (Suzhou Kunqu Theatre), Nanjing (Jiangsu Province Kunqu Theatre), Chenzhou (Hunan Kunqu Theatre), Yongjia County/Wenzhou (Yongjia Kunqu Theatre) and Hangzhou (Zhejiang Province Kunqu Theatre), as well as in Taipei. Non-professional opera societies are active in many other cities in China and abroad, and opera companies occasionally tour.

There are many plays that continue to be famous today, including The Peony Pavilion and The Peach Blossom Fan, were originally written for the Kunqu stage. In addition, many classical Chinese novels and stories, such as Romance of the Three Kingdoms, Water Margin and Journey to the West were adapted very early into dramatic pieces.

Its melody or tune is one of the Four Great Characteristic Melodies in Chinese opera.