People of the Book or Ahl al-kitāb (Arabic: أهل الكتاب) is an Islamic term referring to those religions which Muslims regard as having been guided by previous revelations, generally in the form of a scripture. In the Quran they are identified as the Jews, the Christians, the Sabians, and—according to some interpretations—the Zoroastrians. Starting from the 8th century, some Muslims also recognized other religious groups such as the Samaritans, and even Buddhists, Hindus, and Jains, as People of the Book.

Historically, the religious communities recognized by Muslims as People of the Book were subject to the legal status known as dhimma ('protection'), meaning that they were allowed to practice their faith and to govern their community according to the rules and norms of their own religion, in return for paying a special head tax called the jizya.

The Quran uses the term in a variety of contexts, from religious polemics to passages emphasizing the community of faith among those who possess monotheistic scriptures.

In Islamic law, Muslim men are permitted to marry women who are People of the Book; however, Muslim women are prevented from marrying men who are People of the Book. In the case of a Muslim-Christian marriage, which is to be contracted only after permission from the Christian party, Christian women should not be prevented from attending church for prayer and worship.

The term 'People of the Book' has been reappropriated as a means of self-identification by Jews and by the members of certain Christian denominations.