Diego de Ordaz (also Diego de Ordás; 1480 in Castroverde de Campos, Zamora province, Spain – 1532 in Venezuela) was a Spanish explorer and soldier.
Diego de Ordaz arrived in Cuba at a young age. Serving under the orders of Diego Velázquez, he participated in the earliest exploratory expeditions to Colombia and Panamá.
De Ordaz accompanied Hernán Cortés on his expedition of conquest to the Mexican mainland. He was recognized for his contribution to the victory over the Aztecs obtained at the Battle of Centla near Río Grijalva in Tabasco on March 25, 1519.
Together with two comrades, he was the first European to climb to the top of the volcano Popocatépetl - a feat which made a great impression on the indigenous allies accompanying Cortės. In recognition of De Ordaz's military deeds, the emperor Charles V on October 22, 1525 issued a decree permitting him to use a coat-of-arms featuring a view of the volcano.
De Ordaz participated in the Spanish conquest of Tenochtitlán, the Aztec capital. When prior to the final conquest, the Spaniards were forced to flee from the capital in a nocturnal action known as La Noche Triste ("the sad night"), De Ordaz was wounded.
Following the conquest of Mexico, De Ordaz explored the areas of Oaxaca and Veracruz, and navigated the Río Coatzacoalos.
In 1521, he was sent back to Spain in order to present the story of the conquest of Mexico to the Spanish court, and in order to obtain for Cortės the title of Governor and General Captain of New Spain.