Marie Alphonse Nicolas Joseph Jongen (14 December 1873 – 12 July 1953) was a Belgian organist, composer, and music educator.

In 1892 he was awarded the gilt medal in the piano competition, and later that same year he joined the organ class of Charles-Marie Danneels.

His opus 3, the monumental and massive First String Quartet, was composed in 1894 and was submitted for the annual competition for fine arts held by the Royal Academy of Belgium, where it was awarded the top prize by the jury.

[1] In 1897, he won the Belgian Prix de Rome, which allowed him to travel to Italy, Germany and France over a four year period, during which (among many others) he encountered Richard Strauss, Vincent D'Indy and Florent Schmitt.

With the outbreak of World War I, he and his family moved to England, where he founded a piano quartet with violinist Désiré Defauw, violist Lionel Tertis, and cellist Émile Doehaerd.

[9] Numerous eminent organists of modern times (such as Virgil Fox, Alexander Frey, Jean Guillou, Michael Murray, Diane Meredith Belcher and Olivier Latry) have championed and recorded it.