Gabriel Astruc (1864-1938), a French impresario of Jewish background, is mostly known for his collaborative work as an impresario with Sergei Diaghilev and his Ballets Russes. His role within Parisian musical culture at the fin de siècle, however, was much broader. He was a critic, creator of a leading periodical, producer of musical and circus events, music publisher, and associate of many important cultural figures of his day. Although Astruc has been mentioned in scholarly literature, his multifaceted activities have never been carefully studied. Following the revisionist initiatives of previous scholars (e.g., Pasler, Huebner, Garafola, Fauser), this project offers a new understanding of Parisian cultural life between 1880 and 1913. Rather than focusing on valued composers such as Debussy or selected avant-garde repertoire, this dissertation considers the panoramic perspective of the Parisian cultural milieu as understood by a well-positioned impresario who participated in diverse, but often intersecting, music circles. It reveals rich interconnections between Astruc’s entrepreneurial, managerial, and publishing endeavors that linked private fêtes and soirées that he produced in elite homes with his ambitious concert series, La Grande Saison de Paris, 1905-1913 – organized through his firm La Sociéte Musicale – and with compositions and contents published in Musica, the magazine he co-founded in 1902. It questions Astruc’s aesthetic preferences and argues that he helped to shape Parisian culture through the promotion, publication, and programming of balanced, eclectic repertoire of new and old, national and international, and light as well as weighty works. This study also chronicles the development of the Théâtre des Champs-Élysées, Astruc’s culminating project that was intended to embrace symphonic, operatic, and chamber performance and to experiment with new juxtapositions and integrations of the arts. Research for this dissertation centered on a compilation and a comparative analysis of wide-ranging materials found in Astruc’s collections at the Archives Nationales and New York Public Library. Unlike earlier studies of fin-de-siècle Paris, this project utilizes previously unexamined publications, musical criticism, published literature, and manuscript material, all originating from or related to Astruc’s diverse activities and observations.