Kostiantyn Ivanovycz Ostrozky (c. 1460 – 10 August 1530) (Ukrainian: Костянтин Іванович Острозький , Kostjantyn Ostroz'kyj, Lithuanian: Konstantinas Ostrogiškis, also known under his Ruthenian name Vasyl-Kostjantyn Ostroz'kyj and modern Belarusian transliteration Kanstancin Astrožski) was a magnate of the Grand Duchy of Lithuania and later a Grand Hetman of Lithuania from 11 September 1497 until his death.