William of Orange (French: Guillaume, Dutch: Willem) is the name of several historical people. In the context of Irish and British history, it refers most often to William III of England; in the context of Dutch history, it is usually in reference to William the Silent.

In general, these men could be meant by William of Orange (chronological):

• Saint William of Gellone (755-c.812), legendary courtier of Charlemagne who defeated the Saracens at Orange, is often called William of Orange.
• William, Bishop of Orange joined the First Crusade. After the death of Adhemar of Le Puy, he was recognized as leader of the clergy, until he himself died six months later in December of 1098.

The following princes of Orange were also known as William of Orange:

• William I of Baux (c.1155-1218)
• William II of Baux (c.1200-1239)
• William III of Baux (c.1220-1256)
• William IV of Baux (c.1240-1281)
• William VIII of Chalon (c.1415-1475)

After the counts of Nassau inherited the principality, the following princes of Orange-Nassau (and stadtholders in the Netherlands) were also known as William of Orange:

• William (1533-1584), Prince of Orange, Count of Nassau(-Dillenburg), Lord of Egmond, Count of Buren, founder of the House Orange-Nassau (and so known as William of Orange-Nassau), Stadtholder of Holland, Zeeland and Utrecht, later Stadtholder of Friesland, best known as William the Silent (In Dutch: "Willem de Zwijger"), also known as father of the fatherland (In Dutch: "vader des vaderlands"), Wilhelmus van Nassouwe (as in the Dutch National Anthem composed in his honour), and somewhat ambiguously as William I and as William I of Orange-Nassau (while that is also the correct name for the first king, see below).
• William II of Orange-Nassau
• William III of Orange-Nassau, (1650-1702), also king of England a.k.a. William III of England, William II of Scotland,"King Billy", and William Henry (In Dutch: "Willem Hendrik")
• William IV of Orange-Nassau
• William V of Orange-Nassau

The following kings of the Netherlands from the House of Orange-Nassau may also sometimes be known as William of Orange, particularly as the Heir Apparent to that throne is constitutionally Prince of Orange:

• William I of the Netherlands also known as (King) William I of Orange-Nassau (who was, before his accession, William VI of Orange)
• William II of the Netherlands (The Prince of Orange who fought at the Battle of Waterloo, sometimes known as William VII)
• William III of the Netherlands.
• William, Crown Prince of the Netherlands, eldest son of William III, died before his father and therefore never succeeded as king
• William Alexander, Crown Prince of the Netherlands, the current heir apparent, as eldest son of Queen Beatrix

Wilhelm von Oranien | Guillaume d'Orange | Willem van Oranje (doorverwijspagina) | Vilhelm av Oranien | Vilhelm av Oranien