Léon Boëllmann (September 25, 1862 – October 11, 1897) was a French composer of Alsatian origin, celebrated for his contributions to organ music. Born in Ensisheim, Haut-Rhin, Boëllmann displayed early musical talent and, at the age of nine, was admitted to the École de Musique Classique et Religieuse in Paris. There, he studied under Gustave Lefèvre and Eugène Gigout, excelling in piano, organ, counterpoint, fugue, plainsong, and composition.

After graduating in 1881, Boëllmann became the sub-organist at the Church of St. Vincent de Paul in Paris, later advancing to the position of cantor and organiste titulaire. In 1885, he married Louise, the daughter of his teacher Lefèvre, and was adopted by Gigout, who had no children of his own. Boëllmann taught at Gigout's school and was active in the French musical scene, known for his engaging personality and performances across Paris and beyond.

Boëllmann composed approximately 160 works, spanning various genres, but he is best remembered for his Suite gothique (1895), particularly its Toccata, which remains a staple of the organ repertoire. His compositions reflect a Post-romantic aesthetic, influenced by César Franck and Camille Saint-Saëns, characterized by remarkable sonorities.

Boëllmann's life was cut short at the age of 35, likely due to tuberculosis. After his death, his mentor Gigout raised his three orphaned children, including Marie-Louise Boëllmann-Gigout, who became a distinguished organ teacher. Despite his brief career, Boëllmann's work continues to be celebrated for its innovation and enduring appeal.