The Deer and the Cauldron, also known as The Duke of Mount Deer, is a historical novel by Jin Yong (Louis Cha), the longest of his novels and the last to be published. It was initially published in Hong Kong as a serial, running from 24 October 1969 to 23 September 1972 in the newspaper Ming Pao.

Although the book is often called a wuxia novel, it is not quite typical of the genre: the protagonist, Wei Xiaobao, is not an adept martial artist, but rather an antihero who relies on wit and cunning to get out of trouble.

The novel's title is explained in the first chapter when the poet Lü Liuliang discusses two concepts with his son. The "cauldron" is a reference to a story in the Zuo Zhuan in which King Zhuang of Chu enquired about the Nine Tripod Cauldrons of the Zhou dynasty, unveiling his desire to seize the Mandate of Heaven. The "deer" is a reference to a remark by Kuai Tong recorded in the Records of the Grand Historian: "the Qin emperor lost his deer, and all under heaven chased after it". The deer symbolises the common people of China, who are at the mercy of ruthless warlords vying to conquer the lands of the fallen Qin dynasty.

The title indicates one of the major themes of the novel, the struggle of Han Chinese supporters of the fallen Ming dynasty to free China from the rule of the invading Manchu-led Qing dynasty.

In the afterword, Jin Yong wrote that his intention in writing the novel was to reflect societal and cultural realities instead of encouraging readers to imitate a cunning and evil protagonist. He considered modifying the ending to make Wei Xiaobao get his just deserts, but dropped the idea and retained the original ending after receiving negative feedback from readers.