Jean-Paul Charles Aymard Sartre (21 June 1905 – 15 April 1980), a prominent French philosopher, playwright, novelist, screenwriter, political activist, biographer, and literary critic, is widely regarded as a central figure in 20th-century French philosophy and Marxism. Sartre is celebrated for being one of the key proponents of existentialism and phenomenology, his contributions significantly impacting sociology, critical theory, post-colonial theory, and literary studies. In 1964, he was honored with the Nobel Prize in Literature, which he famously declined, adhering to his principle of refusing official honors, and asserting that "a writer should not allow himself to be turned into an institution."

Sartre's relationship with the renowned feminist and fellow existentialist philosopher Simone de Beauvoir was both personal and professional. Together, they critically questioned the cultural and social norms of their time, advocating for a lifestyle and mode of thought that defied bourgeois expectations. This critique of oppressive conformity versus an authentic existence became a central theme in Sartre's early works, most notably in his magnum opus Being and Nothingness (L'Être et le Néant, 1943). His philosophy is further elaborated in his work Existentialism Is a Humanism (L'existentialisme est un humanisme, 1946), initially delivered as a lecture.