Ostry, Mountain summit in Moravian-Silesian Beskids, Czech Republic.

Ostry is a forest-covered summit at 709 m on the Czech-Polish state border, in the Čantoryjský ridge of the Silesian Beskids. Its cone shape comes from dark marly shales topped by sandstone layers. The red trail from Třinec to Velká Čantoryje passes below the top on the southern slope.

The summit's conical shape comes from its bedrock: dark, marly Wierzów shales capped by Grodzisk and Lgota sandstone layers. The Czech-Polish state border has run across the ridge through the summit, with the red trail from Třinec to Velká Čantoryje passing just below the top on the southern side.

The name Ostry, meaning "sharp" in Czech and Polish, refers to the summit's steep cone shape. The mountain lies on the state border, and scattered settlements of the Czech hamlet Ostry, part of Nydek, spread across its southern slopes.

The summit is accessible via several marked trails from surrounding villages, with different routes offering varying levels of difficulty. Visitors should be prepared for changeable weather and wear proper footwear to navigate the uneven and sometimes slippery paths safely.

The summit's conical shape comes from dark, marly shales known as wierzowskie shales, capped by sandstone layers of the grodziskie and lgockie beds. The same ridge carries the small neighbouring summit Mały Ostry, about 750 m west.