Trostianets (Ukrainian: Тростянець; Polish: Trościaniec) is a village in Stryi Raion, Lviv Oblast, in western Ukraine.

[1] Trostianets is home to the Tortonian sandstone outcrops [uk], a natural landmark of Ukraine.

The outcrops are home to several fossils from the Tortonian age,[2] lending the landmark its name.

According to the 2001 Ukrainian census, the village had a population of 547.

Of this population, all but one citizen spoke Ukrainian natively.