Johann Sigismund Kusser or Cousser (baptised 13 February 1660 – before 17 November 1727) was composer of Hungarian parentage active in Germany, France, and Ireland.
The son of Johann Kusser, a Protestant cantor in Pressburg (now Bratislava), Johann Sigismund and his parents moved to Stuttgart in 1674 because of religious persecution. Two years later he went to spend six years in Paris and the Palace of Versailles. There he met the French court composer Jean-Baptiste Lully and learned from him how to compose in the French style. Kusser was then employed at the princely courts in Baden-Baden and Ansbach, before in October 1683 taking a trip to Germany.
In 1690 he became the first Kapellmeister of the new opera house in Braunschweig. In the following years he married Hedwig Melusine von Damm, daughter of a local Ratsherr. Their daughter Auguste Elisabeth married the Braunschweig chronicler Philipp Julius Rehtmeyer. During his time there, Kusser wrote eight operas, enriching the Italian-influenced repertoire. 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.
At the end of 1704 he moved to London as a composer and private music teacher. In 1707 he went to Dublin and in 1711 was made Chapel-Master of Trinity College, Dublin. 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. Kusser's works are now rarely played, but he influenced the following generation of composers, such as Reinhard Keiser, Johann Mattheson, Georg Philipp Telemann, Christoph Graupner, Georg Caspar Schürmann and Georg Friedrich Händel.
- Composition de Musique (1682), a collection of overtures
- Three collections of suites: Apollon Enjoüé, Festin des Muses and La cicala della cetra d'eunomio (1700)
- Cleopatra (Libretto presumed to be by Friedrich Christian Bressand after Giacomo Francesco Bussani, Giulio Cesare in Egitto), Opera in a prologue and three acts (premiered 4 February 1690 Braunschweig)
- Julia (Braunschweig?), Opera in 3 acts (1690 Braunschweig)
- La Grotta di Salzdahl (Flaminio Parisetti), Divertimento 1 Akt (new year 1691 Braunschweig)
- Narcissus (Gottlieb Fiedler), Opera in prologue and 3 acts (4 October 1692 Braunschweig; Kusser is referred to on the Libretto [Hamburg 1692] as Ober-Capellmeister)
- Andromeda, Singspiel 3 Akte (1692 Braunschweig)
- Ariadne (Bressand), Oper 5 Akte (15 December 1692 Braunschweig)
- Jason (Bressand), Singspiel 5 Akte (1 September 1692 Braunschweig)
- Porus (Bressand, after Jean Racine), Singspiel in 5 acts (1693 Braunschweig); reworked by Christian Heinrich Postel and put on in Hamburg in 1694 as Der durch Groß-Muth und Tapfferkeit besiegte Porus under Kusser's direction
- Erindo oder Die unsträfliche Liebe (Bressand), Schäferspiel 3 acts (1694 Hamburg)
- Der großmütige Scipio Africanus (Fiedler, after Nicolò Minato), Opera in 3 acts (1694 Hamburg)
- Pyramus und Thisbe getreue und festverbundene Liebe (C. Schröder), Opera with prologue (possibly never staged)
- Der verliebte Wald, Singspiel in 1 Act (? Stuttgart)
- Gensericus, als Rom und Karthagens Überwinder (Postel), Opera (1694? Hamburg); dubious attribution, possibly even by Johann Georg Conradi
- The Man of Mode (play by George Etherege) (9 February 1705 London, Little Lincoln's Inn Fields
- Adonis (Score dated 1699 or 1700 found in State Library of Wurttemberg by Dr Samantha Owens ca. 2015)