Iban Graf von Bernstein (born John Kőszegi, also known as John the Wolf; Hungarian: Kőszegi "Farkas" János; 1300s – after 1382) was a Hungarian-born Austrian nobleman in the 14th century. He was a member of the powerful Kőszegi family, of which he became head in 1324. He launched plundering raids against both the Kingdom of Hungary and the Duchy of Austria. After his defeat and downfall in Hungary in 1327, he settled down in Styria and pledged allegiance to the House of Habsburg. Gradually integrating into the Austrian nobility, he became forefather of the Bernstein (or Pernstein) family.