The University Library of Graz (German: Universitätsbibliothek Graz), in the Austrian city of Graz, is the largest scientific and public library in Styria and the third largest in Austria. It holds the right of legal deposit. It is part of the Karl Franzens University of Graz and consists of the main library, two faculty libraries (for law and social and economic sciences, and for theology) and several branch libraries and is open to the public.
The UB Graz owes its origin to the Counter-Reformation. Since 1571 the Jesuits had been pushing the re-catholization in the predominantly Protestant city of Graz according to the wishes of the Archduke Charles II of Austria. For that reason a Jesuit college with a school and a library were founded next to the cathedral in 1573. In 1585 this school was confirmed by Pope Gregory XIII as a Jesuit University, thus the library came into the status of a university library. It grew rapidly because many books got transferred from monasteries to Graz and because of donations and continuous purchases. The university was more or less a theological faculty, and the library's main focus in purchasing books was also theology – but not necessarily Catholic theology. Natural sciences were well represented due to the influence of the mathematician Paul Guldin, who was one of the university professors. When the Jesuit order was abolished in 1773 the university became a state university.
In 1775 the university was officially founded again by a decree and was put under national control together with its library. However, most of the imperial officials who administrated the university as well as the library were former Jesuits. In 1781 the library was re-opened after several adjustments of its new premises and became open for the public for the first time. Unfortunately, the 28 volume library catalogue was untraceable, it might have been taken away or destroyed by some glowering Jesuits and has never been detected until today. The considerable increase of books from monasteries aggravated the chaos.
As well as several other universities the University of Graz was downgraded to the status of lyceum in 1782 by the emperor Josef II. Its collections increased nonetheless.