William I of Aquitaine
| William the Pious | |
|---|---|
 | |
| Duke of Aquitaine | |
| Reign | 893-6 July 918 |
| Predecessor | Ranulf II |
| Successor | William II |
| Born | 22 March 875 |
| Died | 6 July 918 (aged 43) |
| Spouse | Engelberga of Provence |
| Issue | Engelberga Unknown daughter |
| Father | Bernard II of Auvergne |
William the Pious (22 March 875 – 6 July 918), was the Count of Auvergne and Limousin from 886 and Duke of Aquitaine from 893. He founded Cluny Abbey on 11 September 910.