[1] Holdings include approximately 5,200,000 volumes, 1,000,000 e-books, 70,000 e-journals, 2,000 current paper journals, 60,000 Oriental and Western manuscripts, 500,000 letters, 100,000 maps, 100,000 prints, 12,000 drawings, 300,000 photographs and 3,000 cuneiform tablets.

Furthermore, Leiden University Libraries is the only heritage organization in The Netherlands with five registrations of documents in UNESCO's international Memory of the World Register.

Soon, the need for a seat of higher learning was felt and in 1575 Leiden University was founded with the spoils from a confiscated Catholic monastery nearby.

The publication of the catalogue coincided with the opening of the new library on the upper floor of the Faliede Bagijnkerk (now Rapenburg 70) next to the Theatrum Anatomicum.

Readers were able to consult alphabetical and systematic registers of the Leiden library in the form of bound catalogue cards, known as Leidse boekjes.

The litany of 'firsts' recorded at Leiden is dazzling – the first printed catalogue to be prepared by an institution of its holdings, the first attempt to identify and maintain what today are known as 'special collections,' the first systematic attempt to develop a corps of influential friends, patrons, and benefactors throughout the world, the first 'universal' library, the list goes on and on – and underpinning it all is a humanistic approach to education and discovery that has figured prominently throughout its history, along with an unbending belief in the limitless potential of human inquiry."

To accomplish this the library's activities range from supporting education in information literacy to serving as an expert center for digital publishing.

[3] The strategic plan Partner in Kennis (Partner in Knowledge)[4] focuses on the transformation of the library to an expert centre supporting research and education in digital spaces through Virtual Research Environments and Datalabs, the realization of library learning centres, the development of new expert areas such as data curation and text & data mining, and on digital information skills.

[7] The library makes all doctoral dissertations available online through the Catalogue and Leiden University Scholarly Publications[8] that functions according to the open access principles.

Thanks to the use of international standards, among others the Open Archives Initiative, the repository is visited daily by general and specialized search engines that harvest and index this information.

The library of The Netherlands Institute for the Near East, specialised in the fields of Assyriology, Egyptology and Near Eastern Archaeology, became part of UBL in 2018.

[15] Leiden University Libraries hold a large number of special collections of national and international importance.

The collection also includes more than 100,000 printed works from the library of the Maatschappij der Nederlandse Letterkunde which has been deposited on permanent loan since 1876.

The lawyer Johannes Tiberius Bodel Nijenhuis (1797–1872), director of the publishing house Luchtmans, for 25 years a member of the Maatschappij der Nederlandse Letterkunde, was a passionate collector of cartographical and topographical material.

In the course of its expansionist policy the Dutch Republic secured possession of the Indonesian archipelago and other territories in South East Asia.

The Oriental Collections nowadays contain 30,000 manuscripts and 200,000 printed books on subjects ranging from Archaeology to Zoroastrianism and in languages from Arabic to Zulu.

Upon his early death, he left a legacy of 20,000 guilders for the building of a public library ("tot publycque dienst der studie") with a custodian's dwelling.

It is quite extraordinary that a complete private 17th century library has been preserved and thus offers a good impression of the book collection of a young, learned bibliophile from the period of late Humanism.

Whether you are interested in mythological scenes from the Italian Renaissance, daguerreotypes, the largest collection of portraits in the Netherlands, stereophotography or Dutch landscapes by Rembrandt and his pupils, the Print Room has them.

The photography collection spreads from its earliest history to the present day and boasts examples of virtually every Dutch photographer, from anonymous nineteenth-century pioneers through Piet Zwart and Paul Citroen to Ed van der Elsken and Johan van der Keuken, including a lot of attention to present day photographers such as Erwin Olaf and Hendrik Kerstens.

The KITLV was founded in 1851 and created the foremost collections on Southeast Asia (especially on Indonesia) and the Caribbean (especially Suriname, Aruba and the Netherlands Antilles).

On 1 July 2014, the management of the collection was transferred from the Royal Netherlands Academy of Arts and Sciences to Leiden University Libraries.

[19] These include the Brill, Elsevier, Lingling Wiyadharma, Van de Sande, Juynboll en Ailion fellowships, which focus on different disciplines or regions.

The institute was named after Josephus Justus Scaliger (1540–1609), Leiden's most renowned scholar during the early years of its existence and a great benefactor of the University Library through the donation, at his death, of his exceptional collection of manuscripts and all his oriental books.