This PhD thesis follows a threefold editorial, genetic, and literary approach. Jean Vilar holds a prominent place in social and theatrical history as the founder and director of the Avignon Festival (1947–1971), the director of the Théâtre National Populaire (1951–1963), as well as an actor, director, and troupe leader. Additionally, Vilar was a prolific writer whose original ambition was to become an author. This thesis refutes the idea of competition between literary and theatrical vocations. The practice of writing enriches his theatrical research, and his position as director fosters a body of correspondence and work diaries where a distinct style, recognizable tone, and vision of the world emerge. The editorial approach focuses on the creation of a corpus of 328 letters, most of which are previously unpublished, transcribed, classified, and annotated. These letters reflect Vilar’s exchanges with theatrical, literary, political, and intellectual figures from the post-war period to the 1970s. Vilar’s work diary, entitled "Mémento", has been fully transcribed and annotated for the period from 1952 to 1970. It consists of three notebooks, of which only the first and the beginning of the second had been published. This study presents and analyzes the third, previously unpublished, which Vilar maintained from his resignation from the TNP until his death. The genetic approach compares the different versions of the "Mémento", from the initial logbook to its later rewritings. What perspective does the retired artist take on the past, and how does he transform it? What image of his work and of himself does he construct for posterity? How does this self-rewriting blend the journal between a logbook and a professional autobiography? Finally, the literary analysis of the corpus aims to study the characteristics of Vilar’s writing as a letter-writer and diarist, highlighting its specificity, based on a combination of high professional standards and tender friendship.