Baron Jacob Adolphe Reinach[1] (17 April 1840 – 19 November 1892), known as Jacques de Reinach was a French banker of Jewish German origin, involved in many major financial deals before being brought down by the Panama scandals.

He was the son of Clementine Oppenheim (1822–1899) and her husband Adolphe de Reinach (1814–1879), Belgian consul in Frankfurt, ennobled in Italy in 1866 and then confirmed as a noble by William I of Germany.

He settled in Paris at the end of the 1850s and in 1863 founded the bank Kohn-Reinach with his brother in law, international financier Édouard Kohn [fr].

His hôtel particulier at Parc Monceau became the rendez-vous for political, financial and artistic Paris.

In the 1898 novel Paris, Émile Zola based baron Duvillard on Jacques de Reinach.