Johann Kuhnau (born April 6, 1660, Geising, Saxony [Germany]—died June 5, 1722, Leipzig) was a German composer of church cantatas and early keyboard sonatas.
Kuhnau studied music from boyhood and became cantor at Zittau. From 1684 he was organist at the Church of St. Thomas in Leipzig and was cantor from 1701 until his death. He was succeeded at St. Thomas by J.S. Bach. While also studying law, Kuhnau became musical director of the University of Leipzig and is believed to have written music for other churches in the area as well. He wrote 14 annual cycles of church cantatas, of which only a few remain, but he is best known for his clavier compositions. He introduced into many of his dance suites a prelude in free style. His sonatas are characterized by a feeling for the keyboard as an instrument of romantic expression. The biblical sonatas are program music illustrating such stories as that of David and Goliath. Kuhnau also wrote a satiric novel, Der musickalische Quacksalber (1700; “The Musical Charlatan”), deriding Italian musical affectation.