Baroness Franziska "Fanny" von Arnstein (29 September 1758 – 8 June 1818), born Vögele Itzig, was a Viennese socialite and salonnière and a supporter of both Mozart and Beethoven.

They brought the social influences of Berlin, notably the concept of the intellectual salon, to the Vienna of Joseph II.

The Arnstein mansion at Vienna and her villas at Schönbrunn and Baden bei Wien were regularly used for hospitality.

During the Vienna Congress the Arnstein salon was frequented by celebrities including Beethoven, Wellington, Talleyrand, Hardenberg, Rahel Varnhagen and her husband, the Schlegels, Justinus Kerner, Karoline Pichler, and Zacharias Werner.

In 1814, Fanny von Arnstein introduced a new custom from Berlin, hitherto unknown in Vienna: the Christmas tree.