Xuanxue (simplified Chinese: 玄学; traditional Chinese: 玄學; pinyin: Xuánxué; Wade–Giles: Hsüan²-hsüeh²), sometimes called Neo-Taoism or Neo-Daoism, is a metaphysical post-classical Chinese philosophy from the Six Dynasties (222-589), bringing together Taoist and Confucian beliefs through revision and discussion. The movement found its scriptural support both in Taoist and drastically reinterpreted Confucian sources. Xuanxue, or "Mystic Learning", came to reign supreme in cultural circles, especially at Jiankang during the period of division. The concept represented the more abstract, unworldly, and idealistic tendency in early medieval Chinese thought. Xuanxue philosophers combined elements of Confucianism and Taoism to reinterpret the I Ching, Daodejing and Zhuangzi.

The name first compounds xuan (玄) "black, dark; mysterious, profound, abstruse, arcane." It occurs in the first chapter of the Daodejing ("玄之又玄，眾妙之門"). The word xuan literally depicts a shade of deep, mystical, dark red. Daodejing speaks of the Dao as Xuan, more specifically underpinning the depth, utter impenetrability, and the profound mystery of the Dao.

Xue (學) means "study, learn, learning"; thus, xuanxue is literally the "learning" or "study" of the "arcane", "mysterious", or "profound". Therefore, the meaning of xuanxue can be described as "study of the mysterious or profound".

In Modern Standard Chinese usage, xuanxue can mean "Neo-Taoism", "esoteric", "metaphysics", "spiritualism", or "mysticism". The New Treatise on the Uniqueness of Consciousness by Xiong Shili defines Xuanxue as "dark/obscure/mysterious/profound learning". The concept can be described by such abstractions as "to initiate no action", "emptiness", "one and the many", "root and branches", "having and not having", and the "emotional responses" and "pattern".

In modern Chinese, Xuanxue is also taken to refer to astrology, geomancy and other popular religious arts. Another translation of xuanxue could be "learning of the dark."

Xuanxue arose after the Han dynasty (206 BCE-220 CE) in early Medieval China. It is mainly represented by a few scholars, namely Wang Bi (226-249), He Yan (d. 249), Xiang Xiu (223?-300), Guo Xiang (d. 312) and Pei Wei (267-300). In general, these scholars sought to reinterpret the social and moral understanding of Confucianism in ways to make it more compatible with Taoist philosophy. Xuanxue philosophers of the Han dynasty were concerned with restoring unity and harmony to the land, not by condemning the teachings of the sages, but by interpreting them in new ways. Xuanxue thinkers thereby developed their theories by reinterpreting the relationship between Taoist and Confucian texts through an appreciation of their common themes. Through this syncretic movement, the "Way of Mysterious Learning" (Xuanxue) emerged. These post-Han Confucians saw Han Confucianism as restrictive and out of touch with ordinary society, and sought to incorporate Taoist ideas of natural human behaviour. However, such scholars did not agree on how this incorporation was to be accomplished: some argued that morality came from nature and should be aligned with nature; others argued that it was natural to bypass morality and follow nature directly; another group argued that morality itself was nature and simply needed to be purified from the hypocritical use of Confucianism to restrict individuality. Xuanxue constitutes a major stage in the development of Confucianism as some of their commentaries became standard interpretations of Confucianism during the Tang period.

Two influential Xuanxue scholars were Wang Bi and Guo Xiang, editors and leading commentators on the Daodejing and Zhuangzi, respectively. For instance, the Daodejing exists in two received versions named after the commentaries. While the "Heshang Gong version" explains textual references to Daoist meditation, the "Wang Bi version" does not. Richard Wilhelm said the Wang Bi commentary changed the Daodejing "from a compendiary of magical meditation to a collection of free philosophical aperçus."

One of the major defining features of Zhengshi Xuanxue is the "Pure Conversation" (清談) gatherings that took place among political and intellectual elites from the 3rd century onward, through which intellectuals questioned tradition and shared their ideas during the Wei-Jin and Six Dynasties periods. These sessions were transformed versions of the more politically charged "Pure Criticism" (清議) protests of the later Han, which were, in turn, continuations of political remonstration practices. Much of Xuanxue had become divorced from the realities of life and afforded an escape from it.