Willem IV, Count van den Bergh (24 December 1537, 's-Heerenberg, Gelderland – 6 November 1586, Ulft) was Stadtholder of Guelders and Zutphen from 1581 until his arrest for suspected treason in 1583.
Willem was the son of count Oswald II van den Bergh and Elisabeth van Dorth. He spent time at the court of the Regent Mary of Austria (1505–1558) of the Habsburg Netherlands in Brussels at the same time that his contemporary William the Silent, Prince of Orange was educated there. He married the elder sister of Orange, Maria of Nassau, on November 11, 1556 at Moers.
In 1566 he was a prominent member of the League of Nobles (also known as the Compromis) that presented a petition of grievances about the suppression of heresy to the Brussels government of the new Regent Margaret of Parma (who acted for her brother Philip II of Spain). They were derided as Geuzen ("Beggars") for their trouble by a courtier, which epithet would become a name of honor for the future rebels in the Dutch Revolt. This prominence put him in the crosshairs when Fernando Álvarez de Toledo, 3rd Duke of Alba succeeded Margaret as governor-general of the Netherlands in 1567 and started a program of repression. Together with a number of other "ringleaders", like Orange, Willem was indicted before the Council of Troubles, but he escaped with his family to Bremen.