Fadrique Alfonso of Castile, 1st Señor de Haro (1334–1358), 25th Master of the Order of Santiago (1342–1358), was the fifth illegitimate child of Alfonso XI of Castile and Eleanor of Guzman. He was born in Seville.
- Occupation
- politician
- Position held
- Grand Master of the Order of Santiago, Adelantado mayor de la frontera de Andalucía, Great Chamberlain of the King
- Citizenship
- Crown of Castile
- Born
- January 13, 1334
- Died
- May 29, 1358