In Islam, taqiyya (Arabic: تقیة, romanized: taqiyyah, lit. 'prudence') is a concept, that allows for the concealed or dissimulated practice of religious beliefs and actions, often when one's life, property, or community is under threat.

The practice of concealing one's beliefs has existed since the early days of Islam; early Muslims did so to avoid persecution or violence by non-Muslim governments or individuals.

The use of taqiyya has varied in recent history, especially between Sunni Muslims and Shia Muslims. Sunni Muslims gained political supremacy over time and therefore only occasionally found the need to practice taqiyya. On the other hand, Shia Muslims, as well as Sufi Muslims developed taqiyya as a method of self-preservation and protection in hostile environments.

A related term is kitmān (lit. 'action of covering' or 'dissimulation'), which has a more specific meaning of dissimulation by silence or omission. This practice is emphasized in Shi'ism whereby adherents are permitted to conceal their beliefs when under threat of persecution or compulsion.

Taqiyya was initially practiced under duress by some of Muhammad's companions. Later, it became important for Sufis, but even more so for Shias, who often experienced persecution as a religious minority. In Shia theology, taqiyya is permissible in situations where life or property are at risk and whereby no danger to religion would occur. Taqiyya has also been politically legitimised in Twelver Shi'ism, to maintain unity among Muslims and fraternity among Shia clerics.

The term taqiyya is derived from the Arabic triliteral root wāw-qāf-yā denoting "caution, fear", "prudence, guarding against (a danger)", "carefulness, wariness". In the sense of "prudence, fear" it can be used synonymously with the terms tuqa(n), tuqāt, taqwá, and ittiqāʾ, which are derived from the same root. These terms also have other meanings. For example, the term taqwá generally means "piety" (lit. 'fear of God') in an Islamic context.

A related term is kitmān (Arabic: كتمان), the "action of covering, dissimulation". While the terms taqiyya and kitmān may be used synonymously, kitmān refers specifically to the concealment of one's convictions by silence or omission. Kitman derives from Arabic katama "to conceal, to hide". Ibadis used kitmān to conceal their Muslim beliefs in the face of persecution by their enemies.

The technical meaning of the term taqiyya is thought^{[by whom?]} to be derived from the Quranic reference to religious dissimulation in Sura 3:28: