Laozi (; also Lao Tse, Laotze, Lao Zi, and other variations) was a philosopher of ancient China and is a central figure in Taoism (also spelled "Daoism"). Laozi literally means "Old Master" and is generally considered an honorific. Laozi is revered as a god in religious forms of Taoism. Taishang Laojun is a title for Laozi in the Taoist religion, which refers to him as "One of the Three Pure Ones".

According to Chinese tradition, Laozi lived in the 6th century BC. Historians variously contend that Laozi is a synthesis of multiple historical figures, that he is a mythical figure, or that he actually lived in the 4th century BC, concurrent with the Hundred Schools of Thought and Warring States Period.Kohn (2000). Pg 4. Laozi was credited with writing the central Taoist work the Daodejing (Tao Te Ching), which was originally known simply as the Laozi.

A central figure in Chinese culture, both nobility and common people claim Laozi in their lineage. Zhuangzi, widely considered the intellectual and spiritual successor of Laozi, had a notable impact on Chinese literature, culture and spirituality. Throughout history, Laozi's work was embraced by various anti-authoritarian movements.

The Tao Te Ching or Daodejing (), originally known as the eponymous Laozi or Lao tzu (), is a Chinese classic text. Its name comes from the opening words of its two sections: ? dào "way," Chapter 1, and ? dé "virtue," Chapter 38, plus ? j?ng "classic." According to tradition, it was written around the 6th century BCE by the Taoist sage Laozi (or Lao Tzu, "Old Master"), a record-keeper at the Zhou Dynasty court, by whose name the text is known in China. The text's true authorship and date of composition or compilation are still debated.Eliade (1984), p.26

The Tao Te Ching is fundamental to the Taoist school (Dàoji? ) of Chinese philosophy and strongly influenced other schools, such as Legalism and Neo-Confucianism. This ancient book is also central in Chinese religion, not only for Taoism (Dàoji?o ) but Chinese Buddhism, which when first introduced into China was largely interpreted through the use of Taoist words and concepts. Many Chinese artists, including poets, painters, calligraphers, and even gardeners have used the Tao Te Ching as a source of inspiration. Its influence has also spread widely outside East Asia, aided by hundreds of translations into Western languages.

The Wade-Giles romanization Tao Te Ching dates back to early English transliterations in the late 19th century, and many people continue using it, especially for words and phrases that have become well-established in English. The pinyin romanization Daodejing originated in the late 20th century, and this romanization is becoming increasingly popular, having been adopted as the official system by the Chinese government. See discussion at Daoism-Taoism romanization issue.

Taoism (pronounced Daoism) refers to a variety of related philosophical and religious traditions and concepts. These traditions have influenced East Asia for over two thousand years and some have spread internationally.Miller (2003), p. ix. The Chinese character Tao ? (or Dao, depending on the romanisation scheme) means "path" or "way", although in Chinese religion and philosophy it has taken on more abstract meanings. Taoist propriety and ethics emphasize the Three Jewels of the Tao: compassion, moderation, and humility. Taoist thought focuses on wu wei (non-action), spontaneity, transformation and emptiness/omnipotence. An emphasis is placed on the link between people and nature, and that this link lessens the need for rules and order, leading one to a better understanding of the world and one's surroundings.

Nature and ancestor spirits are common in popular Taoism. Organized Taoism distinguishes its ritual activity from that of the folk religion, which some professional Taoists (Daoshi) view as debased. This sort of shamanism is eschewed for an emphasis on internal alchemy among the "elite" Taoists.

Chinese alchemy, astrology, cuisine, several Chinese martial arts, Chinese traditional medicine, fengshui, and many styles of qigong breath training disciplines are intertwined with Taoism throughout history.