Joseph Reinach (30 September 1856 – 18 April 1921) was a French author and politician.
He was born in Paris. His two brothers Salomon and Theodore would become well known in the field of archaeology. After studying at the Lycée Condorcet he was called to the bar in 1887. He attracted the attention of Léon Gambetta by writing articles on Balkan politics for the Revue bleue, and joined the staff of the Republique française. In Gambetta's grand ministère, Reinach was his secretary, and drew up the case for a partial revision of the US Constitution and for the electoral method known as the Scrutin de Liste. In the République française he waged a steady war against General Boulanger which resulted in three duels, one with Edmond Magnier and two with Paul Déroulède. Between 1889 and 1898 he sat for the Chamber of Deputies for Digne.
As a member of the army commission, reporter of the budgets of the ministries of the interior and of agriculture he brought forward bills for the better treatment of the insane, for the establishment of a colonial ministry, for the taxation of alcohol, and for the reparation of judicial errors. He advocated complete freedom of the theatre and the press, the abolition of public executions, and denounced political corruption of all kinds. However, he was indirectly implicated in the Panama scandals through his father-in-law, Baron de Reinach; as soon as he learned that he was benefiting by fraud, he made appropriate restitution. Reinach is best known as the champion of Alfred Dreyfus. At the time of the original trial he attempted to secure a public hearing of the case, and in 1897 he allied himself with Scheurer-Kestner to demand its revision. He denounced in the Siècle the Henry forgery, and Esterhazy's complicity. His articles in the Siècle aroused the fury of the anti-Dreyfus party, especially as Reinach was himself a Jew and accused by some of taking up Dreyfus's defence on racial grounds. He lost his seat in the Chamber of Deputies, and, having refused to fight Henri Rochefort, eventually brought an action for libel against him. Finally, when what had become known as the "Dreyfus Affair" was resolved and Dreyfus was pardoned, Reinach wrote a history of the case, completed in 1905. Henri Dutrait-Croyon's Joseph Reinach, historien (Paris: A. Savaète, 1905), a violent criticism in detail of Reinach's history, "became a bible for that anti-Semitic section of French public opinion convinced of the culpability of Dreyfus." [1]
In 1906 Reinach was re-elected for Digne. In that year he became a member of the commission of the national archives, and the following year a member of the council on prisons. Reinach was a prolific writer on political subjects. On Gambetta he published three volumes in 1884, and he also edited his speeches.