Horacio Echevarrieta Maruri (15 September 1870 – 20 May 1963) was a Spanish businessman, banker, industrialist, patron of the arts, politician and diplomatic mediator.

Born in Bilbao, the son of a mine owner, Cosme Echevarrieta,[1] he expanded his father's activities and set up businesses in many fields, such as the merchant marine, shipbuilding and real estate.

[4] After being placed under house arrest for his involvement in the 1917 general strike, he stepped down from his post of president of the Chamber of Commerce, gave up his seat in parliament, which was taken over by his political and business ally, Indalecio Prieto,[5] as well as from the leadership of the republicanism that he had inherited from his father.

[8][9] He had extensive dealings with Canaris and in 1925 signed a lucrative contract with Walter Lohmann to supply the German Reichsmarine with German-designed torpedoes[10] and had also built a U-Boat for testing and training.

To recoup the costs of building the submarine, German Naval Command sold it to Turkey,[12] which designated it as Gür.