Vasyl Stefanyk Lviv National Scientific Library of Ukraine since 1940 was named Lviv Subsidiary of Academy of Science (A.S.) Library of Ukrainian SSR, than since 1944 the library was named Lviv Library of A.S. Library of Ukrainian SSR, sicne July 1963 it was Lviv State Scientific Library of USSR Ministry of Culture, in 1969 it became Lviv State Scientific Library of A.S. Library of Ukrainian SSR, since May 1971 it was again renamed as Vasyl Stefanyk Lviv Scientific Library of A.S. Library of Ukrainian SSR. On August 5, 1989, the library aquired status of research institute. Starting from March, 1994, it became Vasyl Stefanyk Lviv Scientific Library of Ukrainian National Academy of Sciences. On April 10, 2008, by the Ukrainian President Yushchenko the library was decreed the national status, remaining submitted to Ukrainian National Academy of Sciences, so now it is named Vasyl Stefanyk Lviv National Scientific Library of Ukraine. One of the biggest Ukrainian libraries was established in 1940 as a result of coalescence of such libraries as: Shevchenko Scientific Society, National House, the Ossolinski National Insttitute, a part of Stavropigiya museum library, Prosvita society, monasteries, ethnic comunities (Armenian, Jewish), private collections (whose owners often were subjected to repressions by NKVD), etc. The Ossolineum house (2 Stefanyka Street) is determined for central library premises. Departments of art, ancient printings and rarities (rare books now), Ukrainian literature (Ukrainica now) were founded on the basis of former Baworowski library and libraries of National House and Shevchenko Scientific Society correspondingly. At pre-war times, famous book connoisseurs and specialists from former Lviv libraries (A. Gensiorskyi, M. Derkach, M. Sheliha) worked here. Such scientists as M. Vozniak, V. Doroshenko, Y. Polianskyi, K. Studynskyi, V. Shchurat, I. Krypyakevych played a significant role in library organization. Since summer 1940, a special department (so called 'special fund'), to which large amount of Ukrainian and foreign literature was brought, began functioning (it was disbanded only in 1991-1993). Before the German-Soviet war, Lviv Subsidiary of A.S. Library of Ukrainian SSR funds numbered approximately 2 mln of preservation units.

During the World War II, German authorities joined Lviv scientific libraries ( libraries of university, Shevchenko Scientific Society (SSS) and National House, Ossolinski Institute, also pedagogical and technical libraries) into the single network - Staatsbibliothek Lemberg. During the time of German occupation, the library was robbed for several times. The most dramatic was the loss of A. Durer's original engravings. In 1944 the most valuable collections of books, manuscripts, ancient printings (300 inculabulas) and over 2 thousand of art works were exported to Warsaw. A part of the fund, including valuable manuscript collection of Ukrainica, was found in Nyzhnya Seleziya in 1946, but it hasn't returned to Lviv. Nowadays, collection of SSS library manuscripts department are stored in Poland, in National Libary of Warsaw and National Ossolinski Institute in Wrozlaw.

The library suffered significant losses at post-war time. By soviet government orders, over 217,000 preservation units, including manuscripts and ancient printings, which made 70 per cent of Ossolineum fund, also valuable archive of Ivan Vagylevych were exported to Poland within "a transfer of Polish national historical and cultural values to the Polish Provisional Government of National Unity". Such transfers to Poland were also conducted afterwards (the last one in 1987). In 1949 10,000 volumes were exported to Moscow to the A.S. Library of USSR.

A few valuable private funds of Ukrainian writers and scientists were taken to Kyiv in 1950s. Archives of Ivan Franko, Lesya Ukrainka, Olena Pchilka, O. Makovei, A. Krushelnickyi et al. were taken to the Institute of Literature of UNAS (Ukrainian National Academy of Sciences); collections of V. Hnatyuk and SSS Ethnographic commission were transfered to the Institute of Art Studies, Folklore and Ethnography of UNAS; collections of F. Vovk - to the Institute of Archaeology of UNAS, and collections of Greek-catholic metropolitan consistory - to the Vernadsky Central National Library accordingly. In 1952 huge amount of Ukrainian works of art from 'special fund' was destroyed.

In diffeerent periods T. Zelenko, academician of A.S. of Ukrainian SSR V. Shchurat, A. Odukha, I. Ivantsiv, V. Mashotas, Ye. Stasyuk, M. Lizanets were directors of the library. In 1991-2003, Doctor of History, professor L. I. Krushelnytska was the head of the library, and since 2003 it is governed by Doctor of History, professor M. M. Romanyuk.