The future Teresianum Library began in 1735, in the premises of the General Curia of the Discalced Carmelites in Rome. In 1896 it was given a large part of the library of Card. Raffaele Monaco La Valletta, who died that year. When, at the beginning of the twentieth century, it was planned to found the International College in Rome, almost all the Provinces of the Order offered books for the bibliographical collections of the Order’s academic centre. The library of the Carmelite Cardinal Gerolamo Maria Gotti (†1916) and the books that arrived from the provinces for the inauguration of the International College in 1926 further increased the Library.

In 1954 the International College, where the Faculty of Theology had already been in existence for twenty years, moved to the new building constructed near the Basilica of St Pancras, and here the Library found its permanent home. There was no shortage of opportunities to increase the already considerable number of volumes: first the Missionary Library of the Discalced Carmelite Missionary Seminary, which had existed for many years, was incorporated; then came a bequest by Cardinal Adeodato Giovanni Piazza O.C.D. (†1957). Finally, in 1962, a stock of 11,000 volumes on the ecclesiastical sciences was acquired from the collection left by the antiquarian Attilio Nardecchia (†1961). Thanks to the work of the successive Librarians and their collaborators, the Library is continually being enriched by the acquisition of new publications.

Following the renovation work carried out since 1994, the Library has new and larger premises: a bright Reading Room, with adjacent offices on the second floor of the building, and the large storage room on the ground floor, equipped with compact shelving.

Electronic cataloguing began in spring 1997. The catalogue is available online. In 2014, the number of books available for free consultation in the Reading Room was increased and the furniture was renewed. Currently, the Library holds about 410,000 volumes and 400 periodicals covering all fields of theology. Particular importance is given to the areas of dogmatics, spirituality, anthropology, and Carmelite studies. The Library’s holdings also include the Hagiographic Fund (documents relating to the causes of beatification and canonisation) and a considerable number of old and rare books (about 10,000), including the first editions of the works of St. Teresa of Jesus and St. John of the Cross.

Finally, the Library has the privilege of preserving the doctoral theses that the Congregation for Catholic Education has entrusted to the Teresianum for cataloguing, deposit and safekeeping, so that they can be made available to scholars.

During the academic year 2014-2015, the new Library Regulations were approved. In the spring of 2016, the new integrated programme (KOHA) went into operation, allowing for better management of the OPAC, cataloguing, lending and administration. In addition, all articles published in the journal Ephemerides Carmeliticae, now Teresianum from 1947 to the present day have been included in the catalogue and can be freely consulted.