Cai Lun (Chinese: 蔡伦; courtesy name: Jingzhong (敬仲); c. 50–62 – 121 CE), formerly romanized as Ts'ai Lun, was a Chinese eunuch court official of the Eastern Han dynasty. He occupies a pivotal place in the history of paper due to his addition of pulp via tree bark and hemp ends which resulted in the large-scale manufacture and worldwide spread of paper. Although traditionally regarded as the inventor of paper, earlier forms of paper have existed since the 3rd century BCE, so Cai's contributions are limited to innovation, rather than invention.

Key figuresCai Lun