Karl Jakob Wagner (* 22 Feb. 1772, Darmstadt; † 24 Nov. 1822 ibid.) was a German Kapellmeister and composer. Wagner, a pupil of Johann Gottlieb Portmann and Georg Joseph Vogler, joined the Darmstadt court orchestra as a musician's apprentice in 1788. He was permanently employed as first horn player in 1790, in 1800 also as military music master, in 1808 (after several concert tours) as concert master and finally in 1809 as successor to Georg Sartorius as court conductor. Wagner's pupils included Christian Rummel and Georg Thurn.
Wagner created instrumental and vocal works in a wide variety of compositions and genres. A large part of his unpublished works (operas, drama and church music, cantatas etc. as well as numerous instrumental compositions) were destroyed in Darmstadt in 1944.
