Guanzi may refer to:
- Guan Zhong (管仲, or Guanzi 管子 "Master Guan"), Chinese Legalist philosopher and politician
- Guanzi (text) (管子 "[Writings of] Master Guan"), Chinese text named after Guan Zhong
- Guan (instrument) (管, or guanzi 管子), Chinese double reed instrument
The Guanzi is an ancient Chinese political and philosophical text that is named for and traditionally attributed to the 7th century BCE philosopher Guan Zhong, who served as Prime Minister to Duke Huan of Qi. At over 135,000 characters long, the Guanzi is one of the longest early Chinese philosophical texts. The Han Dynasty scholar Liu Xiang edited the received Guanzi text circa 26 BCE, containing a wide variety of material from many different authors over several successive centuries, largely associated with the 4th century BCE Jixia Academy in the Qi capital of Linzi.
Most Guanzi chapters deal with government and the art of rulership. A number of chapters also express what may be considered a blend of Legalistic, Confucian, and Daoistic philosophy that has been termed " Huang-Lao". The first reference to the collection appears in another such text, the more Taoistic Huainanzi of the early Han dynasty. Considering their tone generally less strident than in the classic Legalist work, the Book of Lord Shang (Shang jun shu 商君書), translator Allyn Rickett dissents from the traditional Confucian view of the texts as Legalist, judging them to "present a point of view much closer to that of the realistic Confucian, Xunzi than either the highly idealistic Confucianism of Mencius or the Draconian Legalism advocated by Shang Yang." Many include Confucian values as a necessity for the state.