Diego de Almagro (Almagro, Spain, c. 1475 – Cuzco, Peru, July 8, 1538), also known as El Adelantado and El Viejo (The Elder), is a Spanish conquistador and a companion and later rival of Francisco Pizarro.

He participates in the Spanish conquest of Peru and is credited as the first European discoverer of Chile.

Almagro loses his left eye battling with coastal natives in the New World.

In 1525 he joins the Pizarro brothers and Hernándo de Luque at Panama for the conquest of Peru.