Marie-Alexis Castillon de Saint-Victor (1860-1937) was a French composer and conductor, recognized for his contributions to early 20th-century music. Primarily associated with the genres of classical and choral music, his works often reflect the stylistic influences of Impressionism and late Romanticism. Notable works by Castillon include his choral compositions, such as "Messe de la Sainte Croix" and "Messe de Requiem," which showcase his ability to blend traditional liturgical forms with innovative harmonic textures. He also composed orchestral pieces and chamber music, demonstrating versatility across different musical settings. Castillon's impact on music lies in his role as a teacher and conductor, influencing a generation of musicians in France. He was associated with several institutions, including the Paris Conservatory, where he contributed to the development of choral music education. His compositions, while not as widely recognized today, played a part in the evolution of French choral music and reflected the broader cultural movements of his time. Through his dedication to music education and composition, Castillon de Saint-Victor left a lasting legacy in the French musical landscape.