John I, Duke of Opava

John I of Opava (also known as John of Fulnek,, Hanuš Hlubčický, Johann I. von Troppau-Leobschütz; c. 1420 – 1454) was a member of the Opava branch of the Bohemian Přemyslid dynasty. He was co-ruler of Opava and Głubczyce from his father's death (between 1445 and 1447) and his own death. He was also Lord of Fulnek.

Life
His parents were Duke Wenceslaus II of Opava and Głubczyce and Elisabeth of Kravař.

After his father's death (between 1445 and 1447) John I and his younger brother John II "the Pious" jointly inherited the Duchy of Głubczyce and one third of the Duchy of Opava.

John I died unmarried and childless in 1454. His brother inherited his possessions.