The Polish Hussars (/həˈzɑːr/, /həˈsɑːr/, or /hʊˈzɑːr/; Polish: Husaria [xuˈsari.a]), or Winged Hussars, were one of the main types of the cavalry in the Polish-Lithuanian Commonwealth between the 16th and 18th centuries. When this cavalry type was first introduced by the Serbian and Hungarian mercenary horsemen at the beginning of the 16th century, they served as light cavalry banners in the Polish army; by the second half of the 16th century and after Stephen Báthory's reforms, hussars had been transformed into heavily armored shock cavalry. Until the reforms of the 1770s, the husaria banners were considered the elite of the Polish cavalry.
Hussars originated in mercenary units of exiled Serbian warriors, the concept having originated in Serbia in the late 14th century. The oldest mention of hussars in Polish documents date to 1500, although they were probably in service earlier. In the 15th century, light hussars based on those of King Mathias Corvinus were adopted by some European armies to provide light, expendable cavalry units.