Ostrowski (Polish pronunciation: [ɔsˈtrɔfskʲi]; feminine: Ostrowska; plural: Ostrowscy) is a surname of Polish-language origin.
In Poland, the surname is a toponym for many place names that start with 'Ostrow' such as Ostrow-Wielkopolski or Ostrowiec.
In Russia, the surname Ostrovsky may have indicated someone who hailed from the Russian city of Ostrov.
It is related to a number of surnames in other languages.