Hedi Stadlen (6 January 1916 – 21 January 2004), better known in Sri Lanka as Hedi Keuneman, was an Austrian Jewish philosopher, political activist, and musicologist. She was one of the handful of European Radicals in Sri Lanka.
She was born Hedwig Magdalena Simon in Vienna to Else Reis and Hans Simon, an eminent economist and banker. She was one of those whose life was deeply affected by the spread of virulent fascism in Europe in the 1930s. Both her parents were assimilated, non-observant Jews; her father had Hedi baptised to make sure that she would have antisemitic shopkeepers during the starvation caused by the First World War.
She was sent to a progressive school in Vienna founded by the Polish-Jewish feminist Eugenia Schwarzwald, at whose home Hedi met such figures as the painter Oskar Kokoschka and the architect Adolph Loos. When she was 14, as an atheist she elected under the Austrian Constitution to register as Konfessionslos (religionless).
She studied philosophy at the University of Vienna. One of her lecturers, Professor Moritz Schlick was shot by a deranged student. The student was later paroled, acclaimed as a 'heroic Aryan' and, became a member of the Austrian Nazi party after the Anschluss.