Carl Friedrich Zelter (11 December 1758 – 15 May 1832) was a German composer, conductor and teacher of music.

Zelter became friendly with Johann Wolfgang von Goethe, and his works include settings of Goethe's poems. During his career, he composed about two hundred lieder, as well as cantatas, a viola concerto (performed as early as 1779) and piano music.

Amongst Zelter's pupils (at different times) were Felix Mendelssohn, Fanny Mendelssohn Giacomo Meyerbeer, and Heinrich Dorn. Felix Mendelssohn was perhaps Zelter's favorite pupil and Zelter wrote to Goethe boasting of the 12 year old's abilities. Zelter communicated his strong love of the music of J.S. Bach to Mendelssohn, one consequence of which was Mendelssohn's 1829 revival of Bach's St. Matthew Passion at the Singakademie under Zelter's auspices. This epochal event sparked a general re-evaluation and revival of Bach's works which were then largely forgotten and regarded as old fashioned and beyond resuscitation. Mendelssohn had hoped to succeed Zelter on the latter's death as leader of the Singakademie, but the post went instead to Carl Friedrich Rungenhagen.

Zelter was married to Julie Pappritz in 1796, one year after his first wife, Sophie Eleonora Flöricke, née Kappel, had died. Pappritz was a well known singer at the Berlin Opera. Zelter is buried at the Sophienkirche in Berlin. The violinist Daniel Hope (born 1974) is a direct descendant of Zelter.

Zelter was the author of a biography of Carl Friedrich Christian Fasch, first published in 1801 by J.F. Unger in Berlin.