Balduin Hoyoul (1547-8 – 26 November 1594) was a Renaissance composer of the Franco-Flemish school.
Hoyoul was born in Liège. From the age of 13 he was a singer at the Court in Stuttgart under Ludwig Daser. 1563-64 he was a pupil of Lassus in Munich. In 1589 he took over from his father-in-law as Hofkapellmeister in Stuttgart. In 1593 he applied, unsuccessfully, for the more prestigious court post at Dresden. In 1594 he died of the plague in Stuttgart, and was succeeded in Stuttgart by another pupil of Lassus, Leonhard Lechner.