William IV of Egmont (Dutch: Willem van Egmond) (26 January 1412 – 19 January 1483) was Lord of Egmond, IJsselstein, Schoonderwoerd and Haastrecht and Stadtholder of Guelders.
William stayed most of the time in Guelders, where he supported his brother against his nephew Adolf of Egmond. After the incarceration of his brother, William led the pro-Burgundy party.
On 22 January 1437 William married Walburga of Meurs, Lady of Baer and Lathum, daughter of Frederick IV, Count of Moers (†1448), and Engelberta of Cleves, by whom he had 4 daughters and 3 sons:
John III of Egmont, Count of Egmond, stadtholder of Holland, Zeeland and West-Friesland;
Besides the children from his marriage Van Egmont had four children by different women:
Nicholas of Egmond, was captured on the Valkhof 1478-1481 together with his half-brothers Frederick and William.
Hendrik van Egmond ( -1511), whose mother was Aleid Kreijnck
Frederik van Egmond
Hendrika van Egmond, she married Willem van Tuyl Bulcke Steijn (-1449). He was a son of Willem Willemsz of Tuyll and Maggie Mate Nesse, daughter of Adriaen van Nesse Mate (1385-1435)
He is buried next to his brother, Duke Arnold of Gelderland.