Austrian political theorist, one of the principal leaders of the Viennese revolution of 1848.

As a young assistant physician, Fischhof was the first speaker to address the crowd assembled outside the building of the Austrian estates in Vienna on the morning of March 13, 1848—the first day of the revolution. Rising in a few days to a position of leadership in the Vienna student movement, he was subsequently (May 1848) elected president of the Executive Committee of Security, the ruling force in the Austrian capital through the summer of 1848. A leading member of the short-lived parliaments at Vienna and Kremsier (now Kroměříž, Czech Republic), he played a major role in the drafting of the ill-fated Kremsier constitution. With the final suppression of the revolution (March 1849), he was arrested and briefly imprisoned. Although his full civil rights were restored by a political amnesty in 1867, he refused to reenter public life, maintaining a voluntary exile at Emmersdorf, where he led the quiet life of a political theoretician. He had sketched a dualistic plan for the Habsburg monarchy six years before the 1867 Ausgleich (the compromise allowing the Magyars to dominate Hungary and the German element to rule the rest of the Austrian territories) and later proposed a scheme of federalization for the Austrian half of the empire that included provisions for a national curial system and “international language laws.” These theories of imperial reorganization exerted considerable influence in their day, especially in Czech national circles.