Ladislaus IV of Poland or Wladislaw Vasa (1595-1648), was the son of Sigismund III of Poland (1566-1632), of the House of Vasa, and his wife Anna (1573 - 1598). He reigned as King of Poland from 1632 to 1648.
His father Sigismund, grandson of Gustav I of Sweden, had succeded his father to the Swedish throne in 1592 only to be deposed from the by his uncle Charles IX of Sweden in 1599. This lead to a long standing feud where the Polish kings of the house of Vasa claimed the Swedish throne. Effects of this were the Swedish War (1600-1629).
Ladislaus was also briefly elected Russian Tsar by Russian boyars.
Poland and Sweden were also on opposite sides in the Thirty Years' War (1618-1648).
Ladislaus died in 1648 and was succeeded by his half brother and cousin Jan II Kazimierz.