Sigmund Zois Freiherr von Edelstein, usually referred as Sigmund Zois (Slovene: Žiga Zois, archaic Cojs or Cojz; pronunciation ) (23 November 1747 – 10 November 1819) was a Carniolan nobleman, natural scientist and patron of the arts. He is considered as one of the most influential figures of the Enlightenment Era in the Slovene Lands of Habsburg Austria.
Sigmund's father Michelangelo Zois (1694–1777) was a merchant from Lombardy that moved to Ljubljana, where he made a considerable fortune in dealing with iron and holding mines. His second marriage was to a Carniolan (Slovenian) noblewoman from the family Kappus (also Kapus) von Pichelstein; he was ennobled in 1739 and acquired the right to the title of baron in 1760. He owned large estates both in Carniola and on the Karst Plateau, and Sigmund was born in Trieste, in one of his father's mansions.
The Carniolan noble family Kappus von Pichelstein on Zois's mother's side was a prosperous family that had lived at Kamna Gorica in Upper Carniola for centuries, where the family had owned an iron foundry and an iron mine since the late Middle Ages, perhaps since the 12th century. Marcus Antonius Kappus von Pichelstein (1657–1717) worked as a Jesuit missionary in Sonora (the border region between today’s United States and Mexico). From there he wrote letters to his friends in Vienna and to his relatives in Carniola. In these letters he described discoveries by research expeditions in Arizona and California and described the living conditions, the climate, and other details. Carolus Josephus Kappus von Pichelstein, a nephew of Marcus Antonius, was member of the Academia Operosorum, which was founded in Ljubljana in 1693 after the example of similar academies in Italy. Vladimir Kappus von Pichelstein (1885–1943), a Slovene writer and publisher, was also from the Kappus family.