Oberon, or The Elf King (German: Oberon oder König der Elfen), or simply Oberon, originally known as Huon and Amanda (German: Hüon und Amande), is a romantic Singspiel in five acts by Friederike Sophie Seyler, based on the poem Oberon by Christoph Martin Wieland, which itself was based on the epic romance Huon of Bordeaux, a French medieval tale. It has been named for two of its central characters, the knight Huon and the fairy king Oberon, respectively.
The opera was published in "Flensburg, Schleswig and Leipzig" in 1789, the year Seyler died. Seyler was married to the prominent theatre director Abel Seyler, the founder of the Seyler Theatre Company and a noted promoter of both German opera and William Shakespeare. The opera was dedicated to their common long-time friend and collaborator, the actor Friedrich Ludwig Schröder. Seyler's opera and a plagiarized version by Karl Ludwig Giesecke both enjoyed popularity from the late 18th century. The opera was also an important influence on the libretto of The Magic Flute.
Seyler's libretto formed the basis of Karl Ludwig Giesecke's libretto for the opera Oberon, written for Emanuel Schikaneder's troupe and set to music by Paul Wranitzky. As Giesecke did not credit her, he later came under much criticism for plagiarism, although it soon became evident that his work was based on Seyler's libretto. The opera The Magic Flute, with a libretto by Schikaneder, was to a significant degree based on Giesecke's version of Oberon and thus ultimately on Seyler.