Fiqh is Islamic jurisprudence. Fiqh is an expansion of the Sharia Islamic law—based directly on the Quran and Sunnah—that complements Shariah with evolving rulings/interpretations of Islamic jurists.

Fiqh deals with the observance of rituals and social legislation. There are four prominent Sunni schools of fiqh (Madh'hab) and one school for the Shi'a. A person trained in fiqh is known as a Faqih (plural Fuqaha).

The word fiqh is an Arabic term meaning "deep understanding" or "full comprehension". Technically it refers to the science of Islamic law extracted from detailed Islamic sources (which are studied in the principles of Islamic jurisprudence). The process of gaining knowledge of Islam through jurisprudence, and the body of legal advisements so derived, is known as fiqh.

The historian Ibn Khaldun describes fiqh as "knowledge of the rules of God which concern the actions of persons who own themselves bound to obey the law respecting what is required (wajib), forbidden (haraam), recommended (mand?b), disapproved (makruh) or merely permitted (mubah)".