Friedrich Wilhelm Marpurg (21 November 1718 – 22 May 1795) was a German music critic, music-theorist and composer. He was friendly and active with many figures of the Enlightenment of the 18th century.

Little is known of Marpurg's early life. According to various sources, he studied "philosophy" and music. It is clear that he enjoyed a strong education and was friendly with various leading figures of the Enlightenment, including Winckelmann and Lessing. In 1746, he travelled to Paris as the secretary for a General named either Rothenberg or Bodenberg. There, he became acquainted with important intellectual luminaries, such as the writer and philosopher Voltaire, the mathematician d'Alembert and the composer Jean-Philippe Rameau.

After 1746, he returned to Berlin where he was more or less independent. Marpurg's offer to write exclusively for Breitkopf & Härtel was declined by the firm in 1757. In 1760, he received an appointment to the Royal Prussian Lotteries, whose director he became in 1763, receiving the title of War Councillor. His son, Johann Friedrich Marpurg, who later became a celebrated violinist, was born in 1766.

Marpurg's quarrelsome disposition and his enthusiasm for public polemics made him many enemies. Contemporaries also described him, however, as courteous and open-hearted.

Marpurg published the bulk of his writings on music between 1750 and 1763. After he had attained his lottery position in 1763, he penned two works on this topic but continued to write on wider areas of music.

One of the first (and most influential) works of Marpurg was his tract on the Fugue (1753) which is considered one of the oldest sources for the performance practice of J.S. Bach's Art of the Fugue. His Handbuch bey dem Generalbasse und der Composition and the translation of d'Alembert's Elémens de musique stand at the beginning of Rameau reception in German harmonic theory. Other works treat questions of instrumental performance, vocal music, music history and mathematical music theory. His journal projects continued to promote the institution of German music criticism in the wake of Mattheson and Scheibe; his Kritische Briefe über die Tonkunst contains significant contributions to the theory of meter, the esthetics of the ode and other topics of current interest. His manuscript work on the ancient water organ remained unfinished. The scope and unprecedented clarity of Marpurg's writings on music made him the leading German music theorist of the late eighteenth century; he and his rivals Kirnberger and Schulz made up a distinct "Berlin School" of music criticism and -theory.