Isabel of Beaumont
| Isabel de Beaumont, Duchess of Lancaster | |
|---|---|
| Born | c. 1318 | 
| Died | 1361 Leicester Castle, England | 
| Noble family | Brienne | 
| Spouse(s) | Henry of Grosmont, 1st Duke of Lancaster | 
| Issue | Maud, Countess of Leicester Blanche of Lancaster | 
| Father | Henry de Beaumont, Earl of Buchan | 
| Mother | Alice Comyn | 
Isabel de Beaumont, Duchess of Lancaster, of the House of Brienne (c. 1318 – 1361) was an English-French noblewoman. She was the youngest daughter and child of Henry de Beaumont, Earl of Buchan and Alice Comyn, Countess of Buchan.