| William III | |
|---|---|
 A near-contemporary depiction of William (far left) with his father (far right) and brother (middle). | |
| King of Sicily | |
| Reign | February – October 1194 |
| Coronation | January/February 1194 |
| Predecessor | Tancred |
| Successor | Constance & Henry I |
| Born | c. 1186 Palermo, Kingdom of Sicily |
| Died | c. 1198 Alt-Ems, Swabia, Holy Roman Empire |
| House | House of Hauteville |
| Father | Tancred, King of Sicily |
| Mother | Sibylla of Acerra |
William III (Italian: Guglielmo III; c. 1186 – c. 1198), a scion of the Hauteville dynasty, was the last Norman King of Sicily, who reigned briefly for ten months in 1194. He was overthrown by his great-aunt Constance and her husband Emperor Henry VI.