He graduated in law from the University of Buenos Aires, and participated in the constitutional assembly of 1860. He was a number of times a national deputy and senator. In 1882 he occupied a seat on the Supreme Court of the Province of Buenos Aires. Later he was employed as president of the Provincial Bank, director of the Academy of Jurisprudence, and had a seat in the General Council of Education.
On 12 October 1892 Sáenz Peña was inaugurated president of the country. Weakened by many radical uprisings, on 23 January 1895 he presented his resignation to Congress, which accepted it. The government passed into the hands of José Evaristo Uriburu, who completed the term ending in 1898.