The Congregation for the Doctrine of the Faith (Congregatio pro Doctrina Fidei - CDF) is the oldest congregation of the Roman Curia. There are nine congregations in total. A congregation is a type of department with a jurisdiction of the Roman Curia, the central administrative organism of the Catholic Church. The Congregation for the Doctrine of the Faith was previously known as the Supreme Sacred Congregation of the Roman and Universal Inquisition. Among the most active of these major Curial departments, it oversees Catholic doctrine. The CDF is the modern name for what used to be the Holy Office of the Inquisition, these days it is sometimes simply called the Holy Office.

According to Article 48 of the Apostolic Constitution on the Roman Curia, "The duty proper to the Congregation for the Doctrine of the Faith is to promote and safeguard the doctrine on the faith and morals throughout the Catholic world: for this reason everything which in any way touches such matter falls within its competence."

It was founded in 1542 by Pope Paul III with the Constitution "Licet ab initio", Originally it was called the Sacred Congregation of the Universal Inquisition as its duty was to defend the Church from heresy. The Congregation for the Doctrine of the Faith is the oldest of the Curia's nine congregations. In 1908 the name was changed by the Pope St. Pius X to the Sacred Congregation of the Holy Office. Current name was set in 1965 with Pope Paul VI.

The congregation is now headed by Prefect Cardinal William Joseph Levada, formerly of San Francisco, US. It has a Secretary, His Excellency Msgr. Luis F. Ladaria, S.I., an under-secretary, Fr. Joseph Augustine Di Noia, O.P., a Promotor of Justice Msgr. Charles Scicluna, and a staff of 37, according to the "Annuario Pontificio" or "Pontifical Yearbook." It also has 23 members - cardinals, archbishops and bishops - and 33 consulters. Given the nature of its task, congregation work is divided into four distinct sections: the doctrinal office, the disciplinary office, the matrimonial office and that for priests.

According to the "Activity of the Holy See", the congregation in conformity with its raison d'être, promotes in a collegial fashion encounters and initiatives to «spread sound doctrine and defend those points of Christian tradition which seem in danger because of new and unacceptable doctrines.»

The Congregation for the Doctrine of the Faith and the Vatican Publishing House issue volumes containing the texts of its single documents, as well as articles relative to its work which appear in the daily edition of "L'Osservatore Romano".

When bishops are in Rome for their quinquennial "ad limina" visit, they call on the Congregation for the Doctrine of the Faith, as they do with other dicasteries of the Roman Curia, «for an exchange of information and reciprocal concerns.»

Pontifical Biblical Commission collaborates with the International Theological Commission. Each of which has as president the Archbishop Prefect of Doctrine of the Faith. Congregation holds weekly meetings, usually on Wednesday, which are attended by officials and consultors.