| Consort: | yes |
| Maria of Aragon | |
| Succession: | Queen consort of Castile and León |
| Reign: | - |
| Spouse: | John II of Castile |
| Issue: | |
| Issue-Link: |
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| House: | Trastámara |
| Father: | Ferdinand I of Aragon |
| Mother: | Eleanor of Alburquerque |
| Birth Date: | 24 February 1403 |
| Birth Place: | Crown of Castile |
| Death Place: | Villacastín, Crown of Castile |
| Burial Place: | Santa María de Guadalupe, Spain |
Maria of Aragon (24 February 1403 -) was the Queen of Castile as the first wife of King John II from their marriage in 1420 until her death in 1445. She was the daughter of Ferdinand I of Aragon and Eleanor of Alburquerque.
Maria was married by her brother in his ambition to place his father's issue on the thrones of Castile and Aragon. The marriage took place in simplicity. Maria was occasionally politically active on behalf of her brothers, the princes of Aragon; she disregarded her husband's policy in favor of her brothers and the relationship between Maria and John was somewhat tense.
After her death on 18 February 1445, her husband married Isabella of Portugal and they became the parents of Isabella I of Castile. Maria has no descendants today, her line having gone extinct within a few decades of her death.
Maria and John II of Castile had four children:
| Maria of Aragon | Father: Ferdinand I of Aragon | Paternal grandfather: John I of Castile | Paternal great-grandfather: Henry II of Castile |
| Paternal great-grandmother: Juana Manuel | |||
| Paternal grandmother: Eleanor of Aragon | Paternal great-grandfather: Peter IV of Aragon | ||
| Paternal great-grandmother: Eleanor of Sicily | |||
| Mother: Eleanor of Alburquerque | Maternal grandfather: Sancho Alfonso of Alburquerque | Maternal great-grandfather: Alfonso XI of Castile | |
| Maternal great-grandmother: Eleanor de Guzmán | |||
| Maternal grandmother: Beatrice of Portugal | Maternal great-grandfather: Peter I of Portugal | ||
| Maternal great-grandmother: Inês de Castro |
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