Constance of Castile, Duchess of Lancaster
| Constance of Castile | |
|---|---|
Detail from Froissart's Chronicles, depicting Constance at the surrender of Santiago de Compostela to her husband | |
| Duchess consort of Lancaster | |
| Tenure | 1371–1394 |
| Duchess consort of Aquitaine | |
| Tenure | c. 1390 – 24 March 1394 |
| Born | 1354 Castrojeriz, Castile |
| Died | 24 March 1394 (aged 39–40) Leicester Castle, Leicestershire, Kingdom of England |
| Burial | |
| Spouse | John of Gaunt, 1st Duke of Lancaster |
| Issue | Catherine, Queen of Castile |
| House | Castilian House of Ivrea |
| Father | Peter of Castile |
| Mother | María de Padilla |
Constance of Castile (1354 – 24 March 1394) was a claimant to the Crown of Castile. She was the daughter of King Peter, who was deposed and killed by his half-brother, King Henry II. She married the English prince John of Gaunt, who fought to obtain the throne of Castile in her name, but ultimately failed.