Cesáreo Onzari (February 1, 1903 – January 7, 1964) was an Argentine footballer who played as a left winger.

[3] Although Onzari made a successful career in football, his peak of popularity was on October 2, 1924, during a friendly match between Argentina and Uruguay national teams, played at Estadio Sportivo Barracas.

In the 15th minute,Onzari made a goal from a corner kick, with no other player touching the ball before scoring.

According to La Nación newspaper, 52.000 fans attended the match, which was won by Argentina 2-1 although the Uruguayan team left the field with only 4 minutes to play.

That same year Onzari played for Boca Juniors during the tour that Xeneizes made in Europe.