Bernardino de la Trinidad Gónzalez Rivadavia y Rivadavia (May 20, 1780 – September 2, 1845) was the first president of Argentina, from February 8, 1826 to July 7, 1827 (Buenos Aires, May 20, 1780 - Cadiz, September 2, 1845). He was a politician of the United Provinces of Río de la Plata, Argentina today. He was the first President of the United Provinces of Río de la Plata, to exercise that office between February 8, 1826 and July 7, 1827.

He was educated at the Royal College of San Carlos, but left without finishing his studies. During the British Invasions he served as Third Lieutenant of the Galicia Volunteers. Attended the open City Council on May 22, 1810 voting for the deposition of the viceroy. He had a strong influence on the First Triumvirate and shortly after he served as Minister of Government and Foreign Affairs of the Province of Buenos Aires.

Although there was a General Congress intended to draft a constitution, the beginning of the War with Brazil led to the immediate establishment of the office of President of Argentina; with Rivadavia being the first to be named to the post. Argentina's Constitution of 1826 was promulgated later, but was rejected by the provinces. Strongly contested by his political party, Rivadavia resigned and was succeeded by Vicente López y Planes.