Colonel Nicolas Jean Robert Conrad Auguste Sandherr (6 June 1846 – 24 May 1897) was a French military officer involved in the Dreyfus Affair.
In 1876, his high potential gained him admission in the first class of students at the École supérieure de guerre and he left the academy breveted as a major.
In September 1894, the Statistical Section intercepted a handwritten note found in the wastepaper basket of the German ambassador in Paris, thanks to a household servant in the embassy.
[1] Promoted to colonel on 14 April 1895, Sandherr left his job at the Statistical Section on 1 July that year to take command of the 20th Infantry Regiment at Montauban.
Struck by a general paralysis (a neurosyphilis-incited meningitis), he had to leave active service in December 1896 and succumbed to his sickness before the scandal came to light.