| William XII | |
| Succession: | Count of Auvergne and Boulogne |
| Reign: | 1325-1332 |
| Predecessor: | Robert VII of Auvergne |
| Successor: | Joan I, Countess of Auvergne |
| Birth Date: | c. 1304 |
| Death Date: | 1332 |
| Noble Family: | House of Auvergne |
| Father: | Robert VII of Auvergne |
| Mother: | Blanche of Bourbon |
| Spouse: | Margaret of Évreux |
| Issue: | Joan I, Countess of Auvergne |
William XII of Auvergne (1300–1332) was Count of Auvergne and Count of Boulogne between 1325 and 1332. He was the eldest son of Robert VII of Auvergne and Blanche of Bourbon, daughter of Robert, Count of Clermont.
William married Margaret of Évreux (1307–1351), daughter of Louis, Count of Évreux and Margaret of Artois. William died in 1332.
William and Margaret had: