Taoism (also spelled Daoism) refers to a philosophical or religious tradition in which the basic concept is to establish harmony with the Tao (道), which is the mechanism of everything that exists. The word "Tao" (or "Dao", depending on the romanization scheme) is usually translated as "way", "path" or "principle", although the word also means "nature" as in the nature of all things as well as the natural world. Taoism had not only a profound influence on the culture of China, but also on neighboring countries. While the philosophical Taoism is not institutionalized, the religious Taoism is institutionalized and present in multiple countries. Taoist philosophy is deeply rooted in contemporary China, and is an unavoidable part of modern Chinese life.

Taoist propriety and ethics emphasize the Three Jewels of the Tao: compassion, moderation, and humility, while Taoist thought generally focuses on nature, the relationship between humanity and the cosmos (天人相应); health and longevity; and wu wei (action through inaction). Harmony with the Universe, or the source thereof (Tao), is the intended result of many Taoist rules and practices.

Reverence for ancestor spirits and immortals is common in popular Taoism. Organized Taoism distinguishes its ritual activity from that of the folk religion, which some professional Taoists (Dàoshi) view as debased. Chinese alchemy (including Neidan), astrology, cuisine, Zen Buddhism, several Chinese martial arts, traditional Chinese medicine, feng shui, and many styles of qigong have been intertwined with Taoism throughout history.