Mozi (Chinese: 墨子; pinyin: Mòzǐ;  c. 470 – c. 391 BC), original name Mo Di (墨翟), was a Chinese philosopher during the Hundred Schools of Thought period (early Warring States period). A book named after him, the Mozi, contains material ascribed to him and his followers.

Born in what is now Tengzhou, Shandong Province, he founded the school of Mohism that argued strongly against Confucianism and Taoism. His philosophy emphasized self-restraint, self-reflection and authenticity rather than obedience to ritual. During the Warring States period, Mohism was actively developed and practiced in many states but fell out of favour when the legalist Qin dynasty came to power. During that period, many Mohist classics are by many believed to have been ruined when the emperor Qin Shi Huang supposedly carried out the burning of books and burying of scholars. The importance of Mohism further declined when Confucianism became the dominant school of thought during the Han Dynasty, until mostly disappearing by the middle of the Western Han dynasty.

The concept of Ai (愛) was developed by the Chinese philosopher Mozi in the 4th century BC in reaction to Confucianism's benevolent love. Mozi tried to replace what he considered to be the long-entrenched Chinese over-attachment to family and clan structures with the concept of "universal love" (jiān'ài, 兼愛). In this, he argued directly against Confucians who believed that it was natural and correct for people to care about different people in different degrees. 

"Mozi" is also the name of the philosophical text compiled by Mohists from Mozi's thought. This text originally consisted of 71 chapters. Because Mohism disappeared as a living tradition from China, its texts were not well maintained, and many chapters are missing or in a corrupted state.