Roque José Antonio del Sagrado Corazón de Jesús Sáenz Peña Lahitte was President of Argentina, serving from October 12, 1910, to his death in office on August 9, 1914.
He was the son of former president Luis Sáenz Peña. He was a candidate for an internal line called "modernist" within the National Autonomist Party.
He was responsible for passing Law 8871, known as "Sáenz Peña Law", which greatly reformed the Argentine electoral system, making the vote secret, universal and compulsory for males over 18. This effectively ended the rule by electoral fraud of the conservative Argentine oligarchy, and paved the way for the rise of the Radical Civic Union in the first free elections of the country.