Silesian Ostrava Castle (Czech: Slezskoostravský hrad) is a castle located in Ostrava, in the Moravian-Silesian Region of the Czech Republic. It was originally built in the 1280s for military purposes, near the confluence of the Lučina and Ostravice rivers, near the Polish border.

In 1534, the Gothic castle was rebuilt into a Renaissance residence. It burned down in 1872 but was rebuilt. In 2004, it was repaired after many years of dilapidation, caused by coal mining under the castle.

Until 2012, the castle hosted the Colours of Ostrava festival.

49°49′50″N 18°18′00″E / 49.83056°N 18.30000°E / 49.83056; 18.30000