Lope Díaz III de Haro was a Spanish noble and head of the House of Haro. He was the 8th Lord of Biscay, a post which he gained by hereditary means after the death of his father. He held that title from 1254 until his own death in 1288 when he died attempting to assassinate the King of Castile.
- Occupation
- aristocrat, military personnel
- Position held
- Mayordomo mayor of the King of Castile, Ensign of the Royal Banner of Castile
- Citizenship
- Crown of Castile
- Born
- 1201
- Died
- June 8, 1288, 1288
