István, a király ("Stephen, the King") is a Hungarian rock opera written by Levente Szörényi (music) and János Bródy (lyrics), based on the life of Saint Stephen of Hungary. The storyline was based on the play Ezredforduló (Turn of the Millennium) by Miklós Boldizsár, who co-wrote the libretto.
The opera was first staged in 1983 on an open-air stage in Budapest. This first performance was also made into a 1984 film, directed by Gábor Koltay, and its music released on an album. The musical became a smash hit and is still very popular in Hungary and among Hungarian minorities in neighboring countries.