Johann Sigismund Kusser or Cousser (baptized 13 February 1660 – before 17 November 1727) was a composer born in the Kingdom of Hungary who was active in Germany, France, and Ireland.
Disagreements in 1694 with the librettist and court poet Friedrich Christian Bressand led Kusser to move to the Oper am Gänsemarkt in Hamburg.
He then left Hamburg at the end of 1695 and, after spells working in Nuremberg and Augsburg, took a post at the court of Eberhard Louis, Duke of Württemberg in 1699, being made Hofkapellmeister there the following year.
He was then appointed "Chief Composer" and "Master of the Musick, attending His Majesty's State in Ireland" in 1716, dying in Dublin in 1727.
His tasks included the composition of annual birthday odes for the English king and other festive occasions; his Dublin serenatas were staged like semi-operas.