The House of Orsini-Rosenberg (also Ursin-Rosenberg) is the name of an old Austrian noble family. The family is mediatized and as such belongs to the high nobility. It originally sprang out from the Graben family (an apparent or illegitimate branch of the House of Meinhardin)^[1] from Castle Alt-Grabenhofen near the city of Graz.^[2]

The earliest known member of the Orsini-Rosenberg family, Konrad (von Graben) ab dem Roesenperg, lived around 1322.^[3][4] He was a member of the low nobility who lived at Schloss Alt-Grabenhofen, between Reinerkogel and Rosenberg. During the 17th and 18th centuries, the success of the family arose from the steady accumulation of land, and loyalty to the Habsburg Emperor.

On 2 August 1633, Johann Andreas von Rosenberg, Herr von Rosenberg, was elevated to the Reichsfreiherrenstand with the title of Freiherr of the Holy Roman Empire, Freiherr of Lerchenau, Herr of Magereckh and Grafenstein, and in 1648 to the Austrian Grafenstand. Since 1681, the family held the title of Reichsgraf, and in 1683 they became members of the Reichstag. In the same year, they took the name of the old Italian princely Orsini family; their family name changed to Ursini-Rosenberg or Orsini-Rosenberg. On 9 October 1790, Franz Xaver Wolfgang von Orsini-Rosenberg was elevated to Reichsfürst von Orsini-Rosenberg.

• Johann Andreas von Rosenberg (1600–1667), became first Count of Rosenberg.
• Vinzenz von Orsini-Rosenberg (1722–1794), Landeshauptmann of Carinthia.
• Franz Xaver Wolfgang von Orsini-Rosenberg (1726–1795), diplomat and politician, was made first Count of the Holy Roman Empire of Orsini-Rosenberg and later first Prince of the Holy Roman Empire of Orsini-Rosenberg; he was the basis for the character Count Orsini-Rosenberg in the fictional work Amadeus.
• Prince Franz Seraph of Orsini-Rosenberg (1761–1832), Austrian General of Cavalry.

• Orsini family (Italy)
• Rosenberg family (Bohemia)