Ortiz, who will report to Chuck Brymer, DDB's worldwide chief executive, will oversee about 1,700 staff in more than 22 countries in Central and South America. He will also lead the network's US Hispanic marketing efforts.
Ortiz, 39, succeeds Steve Burton, 55, who shifts to become the chief operating officer for Latin America. Both will be based in Miami.
Brymer said: "Ortiz has a passion for creative environments, the development of creative business solutions and the talent that drives them."