The IX Gymnasium "Mihailo Petrović-Alas" (Serbian: Девета гимназија "Михајло Петровић-Алас", romanized: Deveta gimnazija "Mihailo Petrović-Alas") is a gymnasium located in New Belgrade, Serbia, established in 1961, and named after the Serbian mathematician Mihailo Petrović-Alas.