Hermann Weil (18 September 1868 – 3 October 1927) was a German-Argentine businessman, who in the beginning of the 20th century was the biggest grain trader in the world.

He funded the Institute for Social Research which developed the Frankfurt School of Marxist thought and critical theory.

[1] He was the tenth of 13 children born in a Jewish family to his father Josef Weil (1823-1887) and mother Fanny.

After graduating from a Realschule in Sinsheim in 1883, Weil moved to Mannheim, the then center for European grain trade.

He quickly rose in rank, and began conducting business for Weismann in Switzerland, Antwerp, and the Balkans.

His company expanded quickly, with help of the emerging Argentine grain market and his contacts from Mannheim.

Weil was disgruntled by the political situation in Germany after the war, and expressed his disgust over the increasing Antisemitism present and the murders of Rathenau and Erzberger in a letter to the Lord Mayor of Frankfurt in February 1923.

In total he spent 120 million Marks constructing and maintaining social relief organizations, which helped veterans, orphans, etc.

Weil and his brothers Samuel and Ferdinand, made a fund, whilst in Argentina, to care for their relatives in Germany.