| William IV | |
|---|---|
 Portrait by Kaspar van der Borcht, 1577 | |
| Landgrave of Hesse-Kassel | |
| Reign | 31 March 1569 – 25 August 1592 |
| Successor | Maurice |
| Born | 24 June 1532 Kassel |
| Died | 25 August 1592 (aged 60) |
| Spouse | |
| Issue More... | |
| House | Hesse-Kassel (founder) Hesse (by birth) |
| Father | Philip I, Landgrave of Hesse |
| Mother | Christine of Saxony |
William IV of Hesse-Kassel (24 June 1532 – 25 August 1592), also called William the Wise, was the first Landgrave of the Landgraviate of Hesse-Kassel (or Hesse-Cassel). He was the founder of the oldest line, which survives to this day.