Islamic legal canons are interpretive principles that represent varied conceptions of Islamic law and its values, as they developed over time and space. This chapter argues that Muslim judges and jurists used certain interpretive tools to construct Islamic law’s institutions — legal, judicial and governing —and to promote certain values or policies over others. Approaching Islamic law with an eye on the role that legal canons played in constructing it can help jurists and legal historians chart a fuller and more textured picture of Islamic law. Islamic legal canons appeared right at Islam’s inception and circulated during the ‘founding period’ of the seventh to tenth centuries, and their influence and reach expanded thereafter in central Islamic lands. The Qur’an is the primary source for Islamic law, even though its law-related verses are a minor portion of the full text. Judges and jurists expressed many precedents and procedures in Islamic law through legal canons elaborated through judicial practice, common-law style.