Duchess Maria Isabella Philippine Theresia Mathilde Josephine of Württemberg (German: Maria Isabella Philippine Theresia Mathilde Josephine, Herzogin von Württemberg) (30 August 1871, Orth an der Donau, Lower Austria, Austria–Hungary – 24 May 1904, Dresden, Kingdom of Saxony) was a member of the House of Württemberg and a Duchess of Württemberg by birth and a member of the House of Wettin and a Princess of Saxony through her marriage to Prince Johann Georg of Saxony.

Maria Isabella was the third child and youngest daughter of Duke Philipp of Württemberg and his wife Archduchess Maria Theresa of Austria.

Maria Isabella married Prince Johann Georg of Saxony, sixth of eight children and the second son of George of Saxony, the king of Saxony, and his wife Infanta Maria Anna of Portugal, on 5 April 1894 in Stuttgart. Maria Isabella and Johann Georg did not have children.