- (1353-1369) Eldest daughter of Pedro of Castile and María de Padilla. She was the sworn heir to the throne of Castile, but died in the same year as her father.
- Her father offered her in marriage to Prince Fernando, son and heir of Pedro of Portugal (1358), but the marriage did not take place. Beatriz was even sent to Portugal in 1366 together with her dowry, as her father feared the advance of Enrique of Trastámara, his half-brother, into Castile, and wished to pressure Pedro of Portugal into giving him military assistance. [Pedro, ch. 37: 7-17; ch. 38: 5: 8]
- Pedro IV of Aragon proposed a marriage between his son Juan, heir to the Aragonese crown, and Beatriz, with a view to firming a peace agreement and bring the war between Castile and Aragon to an end, but the King of Castile declined (1363). [Pedro, ch. 34: 61-69]