The Supreme Tribunal of the Apostolic Signatura is the highest judicial authority in the Catholic Church (apart from the Pope himself, who as the supreme ecclesiastical judge, is the final point of appeal for any ecclesiastical judgment). In addition, it oversees the administration of justice in the Church.

The current Prefect of the Supreme Tribunal of the Apostolic Signatura (since June 27, 2008) is Cardinal Raymond Leo Burke, previously Archbishop of St. Louis, Missouri and Bishop of La Crosse, Wisconsin. The current Secretary (since April 12, 2008) is Bishop Frans Daneels, O. Praem..

The Roman Rota is the ordinary appellate tribunal of the Apostolic See. The Signatura's competence covers instead:

Apart from these judicial matters, the Signatura has competence as an administrative tribunal to deal with controversies over administrative decisions made by or approved by departments of the Roman Curia, if it is contended that the decision violated some law either in the decision-making process or in the procedure used; it can also deal with administrative controversies referred to it by the Pope or those departments, and with conflicts of competence between the departments.