Nacionalna i sveučilišna knjižnica u Zagrebu - National and University Library in Zagreb

National and University Library in Zagreb (NSK) (Croatian: Nacionalna i sveučilišna knjižnica u Zagrebu, NSK; formerly Nacionalna i sveučilišna biblioteka u Zagrebu, NSB) is the national library of Croatia and central library of the University of Zagreb.

The Library was established in 1607. Its primary mission is the development and preservation of Croatian national written heritage. It holds around 3 million items.

Since 1995 the NSK has been located in a purpose-built cubical building in central Zagreb.

Services provided include lending and reference services (bibliographic-reference and catalogue information, subject search, science citation index search); interlibrary loan; national bibliographic database; IT services (reprographic services, microfilming, digitization, use of computer equipment); and learning programmes for users. Exhibitions are mounted, and parts of the Library's premises may be leased.