- (1335-1384) Lord of Medina de Pomar and Head Chamberlain to Enrique II of Castile.
- Son of Fernán Sánchez de Velasco.
- Married María Sarmiento, whith whom he had four children: Mayor, Fernando, Juan and Diego. Had two illegitimate sons: Pedro and Sancho.
- Former vassal of Pedro of Castile, made responsible for the defense of the border of Murcia with Aragon.
- In 1360, similarly to many other members of the Castilian nobility, he left Castile to join Enrique of Trastámara's faction in Aragon.
- In 1367 he was arrested by the Black Prince, the ally of Pedro of Castile in the Battle of Nájera.
- When the Count of Trastámara became Enrique II of Castile, Pero Fernández de Velasco was rewarded for his support. He was granted the town and title of Medina de Pomar and was appointed Head Chamberlain to the king.
- Adviser to Enrique II on Castile on what measures to take in order to force King Fernando of Portugal to observe the terms of the peace treaty of Santarém, 1375.
- Died of the plague at the siege of Lisbon, 1384.
Pero Fernandez de Vallasco
Chronicle entries in which Pedro Fernández de Velasco, Lord of Medina de Pomar appears:
Crónica de D. Fernando, ch. 5
Crónica de D. Fernando, ch. 72
Crónica de D. Fernando, ch. 131
Crónica de D. Fernando, ch. 154
Crónica de D. Fernando, ch. 156
Crónica de D. Fernando, ch. 168
Crónica de D. Fernando, ch. 169
Crónica de D. João I, part 2, ch. 106