The Guardian Council of the Constitution (Persian: شورای نگهبان قانون اساسی‎, Shora-ye Negahban-e Qanun-e Assassi), also known as the Guardian Council or Council of Guardians, is an appointed and constitutionally-mandated 12-member council that wields considerable power and influence in the Islamic Republic of Iran.

The Iranian constitution calls for the council to be composed of six Islamic faqihs (expert in Islamic Law), "conscious of the present needs and the issues of the day" to be selected by the Supreme Leader of Iran, and six jurists, "specializing in different areas of law, to be elected by the Majlis (the Iranian Parliament) from among the Muslim jurists nominated by the Head of the Judicial Power," (who, in turn, is also appointed by the supreme leader).

It is charged with interpreting the Constitution of Iran, supervising elections of, and approving of candidates to, the Assembly of Experts, the President and the Majlis, and "ensuring ... the compatibility of the legislation passed by the Islamic Consultative Assembly [i.e. Majlis] ... with the criteria of Islam and the Constitution", i.e., as the watchdog of the constitution it can veto any law passed by the Majlis.