Diego López V de Haro, nicknamed el Intruso (c. 1250 – 1310), was a Spanish noble of the House of Haro and held the title of the Lord of Biscay which he took from the pretender to the title, John of Castile. He further served in the capacity of Mayordomo mayor del rey and the Alférez del rey of Ferdinand IV of Castile. He was a major benefactor of the city of Bilbao, where he expanded the local fishing village and granted it the power to maintain its customs market free of any Portazgo (royal tribute) answerable only to the authority of the Lord of Biscay.