The Załuski Library (Polish: Biblioteka Załuskich, Latin: Bibliotheca Zalusciana) was built in Warsaw in 1747–1795 by Józef Andrzej Załuski and his brother, Andrzej Stanisław Załuski, both Roman Catholic bishops. The library was the first Polish public library, the largest library in Poland, and one of the earliest public libraries in Europe.
The building was destroyed by the Germans during World War II. After the war, it was rebuilt under the Polish People's Republic.
Today's Polish National Library (Biblioteka Narodowa), founded in 1928, considers itself the descendant of the Załuski Library.