The House of Ossoliński (plural: Ossolińscy) is the name of a Polish szlachta (nobility) family. Because Polish adjectives have different forms for the genders, Ossolińska is the form for a female family member.
The Ossolińskis were a magnate family. They appeared in the historical annals at the beginning of the 14th century. The family originated from Ossolin in Lesser Poland. The progenitor of the family was Jan of Ossolin, son of Great Marshal of the Crown and castellan of Kraków Nawoj of Tęczyn. Jan was the main heir of the property that Nawoj left after his death. Due to the tradition in medieval Poland, he started to use the surname derived from the main family seat.Grand Chancellor of the Crown Jerzy Ossoliński was granted a hereditary princely title by Pope Urban VIII in 1633. He also received a similar title, Reichsfürst, from the Emperor Ferdinand II in 1634. Another title was granted to Jerzy's cousin Franciszek Maksymilian Ossoliński by Louis XV, King of France, in 1736. Both titles became extinct in 1790. Józef Maksymilian Ossoliński's famous library assembled in Vienna was transferred to Lwów, where he had located the Ossoliński Institute in 1817.
The Ossoliński family used the "Topór" arms.
The descendants are represented in North Western England through Count Boris Ossolinski, whose Jackson heiress bride is remembered in England as Countess Mary Ossalinsky.