The Ossolineum or Zakład Narodowy im. Ossolińskich (ZNiO, National Ossoliński Institute) is one of the largest scientific libraries and the oldest still existing publishing houses in Poland. It was established in 1817.
The "Ossolineum" was founded by Count Józef Maksymilian Ossoliński in 1817 in Lwów. After the Second World War it was moved to Wrocław in 1947, however only approx. 15-20% was transported, the remainder was confiscated by the Ukrainian authorities with the excuse that if there was any mention of Ukraine, or any territory east of the Curzon Line in any text, they were to remain in Ukraine.