Paul-Louis Landsberg (3 December 1901 – 2 April 1944) was a German Existentialist philosopher who is known for his works The Experience of Death and The Moral Problem of Suicide.

Landsberg lectured at the Universities of Bonn, Madrid and Paris, among others. He was a pupil of Martin Heidegger, Edmund Husserl and Max Scheler, continuing their work in Phenomenology to tackle several vital subjects, including personal identity, death and suicide. He was a close friend of the Christian Existentialist Emmanuel Mounier and a key contributor to the philosophical journal Esprit (1913-2013).

Landsberg was hounded by the Gestapo for most of his life, both because of his Jewish family background and due to his expression of Anti-Nazi sentiments. He was captured by the Gestapo and deported to Oranienburg concentration camp towards the end of the war and died there of physical and mental exhaustion in April 1944.

Paul-Louis Landsberg was born on 3 December 1901 at Bonn into a large, wealthy Jewish family, the son of the prominent German Jurist Ernst Landsberg and his wife Anna. His parents had him baptized as a Protestant but later on he turned towards Catholicism and allied himself with the Benedictine liturgical movement centered around Maria Laach. He was a pupil of the phenomenological philosophers Edmund Husserl, Martin Heidegger (in Freiburg) and Max Scheler. Though he studied with the latter-most in Cologne, he moved back to his birth-town to become Professor of Philosophy at the University of Bonn.

However, due to his opposition to Nazism, he fled Germany just before the coming to power of Adolf Hitler in 1933. By the beginning of March 1933, he had emigrated to Spain and began teaching Philosophy there. During this period he was studying the Mystics of the 16th century. Between 1934 and 1936, he held positions at the Complutense University of Madrid and the University of Barcelona, where his thought began to exert a great influence over his pupils, and where it is still studied avidly to this day.

With the coming of the Civil War in Spain, Landsberg transferred to Paris where he began giving courses at the University of the Sorbonne on the Meaning of Existence. It was at this time that he also became deeply involved with the journal Esprit (1913-2013) through which channel his thought gradually became disseminated.

Landsberg became close friends with the Personalist philosopher Emmanuel Mounier, whose themes bore a similarity to those explored in his own works. A friend of Max Scheler's, and a disciple of some of his Phenomenological techniques, Mounier was like Landsberg a Christian. Along with Gabriel Marcel these were probably the most significant 'Christian Existentialists'. On the other side were, of course, the Atheist Existentialists such as Landsberg's tutor Heidegger, Jean-Paul Sartre and Albert Camus, while Martin Buber was a significant Jewish Existentialist and Simone de Beauvoir, if you like, the leading Feminist Existentialist.

For a long time, Landsberg was persecuted by the Gestapo and it was clear that they were intent on having him put away, if not least for his Anti-Nazist views but also for his essentially Jewish parentage. First his wife Madeleine was taken captive by the Nazis and he spent a long odyssey cycling from town to town in France, both so as to escape from the German Army and in order to find her. He succeeded in joining an Anti-Nazi military group which provided him with official papers, enabling him to take shelter at several locations (Vendôme, Orléans, Lyon) yet always without any news of his wife. The group of the Esprit journal managed to see to the safe storage of some of his works and place him safely (for a moment) at the Psychiatric Asylum in Pau, where he was afforded some recovery from the trauma of being separated from his wife and being detained temporarily by the Nazis.