František Xaver Dušek (German: Franz Xaver Duschek or Dussek); baptised 8 December 1731 – 12 February 1799) was a Czech composer and one of the most important harpsichordists and pianists of his time.
Dušek was born at Chotěborky, which is part of Vilantice, in the Kingdom of Bohemia. He was taught the harpsichord in Vienna by Georg Christoph Wagenseil and established himself around 1770 in Prague as a successful keyboard teacher. Wolfgang Amadeus Mozart was probably his guest in his Villa Bertramka in Košíře, just outside Prague, although no documentation exists to support claims originating in nineteenth-century literature that he stayed there frequently. Mozart himself never reported staying there and no contemporary witness ever reported seeing him there. The best evidence that he ever stayed there comes from a reminiscence of Mozart's son Karl Thomas Mozart that dates from 1856 and indicates that he was at the Bertramka during his second visit to Prague (during October and November 1787). Karl Thomas was not himself a witness to the incident reported, rather he only heard about it from friends of Mozart whom he met as a child in Prague during the 1790s.[1] Furthermore, there is no documentation to support widespread claims that Mozart completed the operas Don Giovanni and La clemenza di Tito at the Bertramka, or indeed that he even worked on them there. Dušek died in Prague. He was a teacher of Mozart's son Karl Thomas, who became a gifted pianist, although he did not pursue a career in music.

Dušek's wife Josepha Hambacher (7 March 1753 – 8 January 1824) had been taught by him and was a famous pianist and soprano. She sang important soprano roles in Mozart operas in early performances, and Mozart's concert aria Bella mia fiamma (catalogued as K. 528) was written for her.[2]

Dušek composed sonatas, variations and concertos for harpsichord and piano and several symphonies and string quartets. Much of his music is in the galant style of the early Classical period.