The Book of Han, Hanshu or History of the Former Han Dynasty (simplified Chinese: 汉书 or 前汉书; traditional Chinese: 漢書 sometimes, 前漢書; pinyin: Qián Hànshū; Wade–Giles: Ch'ien Han Shu) is a classical Chinese history finished in AD 111, covering the history of China under the Western Han from 206 BC to 25 AD. It is also sometimes called the Book of Former Han. The work was composed by Ban Biao, Ban Gu, and Ban Zhao. A second work, the Book of the Later Han covers the Eastern Han period from 25 to 220, and was composed in the fifth century by Fan Ye (398–445). Various scholars have estimated that the earliest material covered in the book dates back to between 206 and 202 BCE. The book also contains the first written historical mention of Japan.

This history developed from a continuation of Sima Qian's Records of the Grand Historian, initiated by Ban Gu's father, Ban Biao, at the beginning of the Later Han Dynasty. This work is usually referred to as Later Traditions (後傳), which clearly indicates that the elder Ban's work was meant to be a continuation. (It should be noted that other scholars of the time, including Liu Xin and Yang Xiong also worked on continuations of Sima's history.) After Ban Biao's death, his eldest son Ban Gu was dissatisfied with what his father had completed, and he began a new history that started with the beginning of the Han dynasty. This distinguished it from Sima Qian's history, which had begun with China's earliest legendary rulers. In this way, Ban Gu initiated the format for dynastic histories that was to remain the model for the official histories until modern times.