Heinrich Klang was born in Vienna where he was raised and attended school. Following his studies in law at the University of Vienna, Klang went into practice and became an expert on civil law. He was appointed an Austrian judge and jurist. Klang taught civil law at the University of Vienna. He edited ,together with others, Kommentar zum Allegemeinen Burgerlichen Gesetzbuch (1931-1935). At the time of the annexation of Austria by Germany (1938), he was presiding judge of the High Court of Vienna. Heinrich Klang was pensioned and in 1942 deported to Theresienstadt Concentration Camp. He survived and returned to Vienna (1945), where he was appointed President of one of the divisions of the High Court.