Johannes Lepsius (15 December 1858, Potsdam, Germany ??3 February 1926, Meran, Italy) was a German Protestant missionary, Orientalist, and humanist.

During World War I he published his work 'Bericht 羹ber die Lage des armenischen Volkes in der T羹rkei' ('Report on the situation of the Armenian People in Turkey') in which he meticulously documented and condemned the Armenian Genocide. A second edition included an interview with Enver Pasha, one of the chief architects of the genocide.

Lepsius had to publish the report secretly because Turkey was an ally of the German Empire and the official military censorship soon forbade the publication because it feared that it would affront the strategically important Turkish ally. However Lepsius managed to distribute more than 20,000 copies of the report.

Today, the intellectual heritage of Johannes Lepsius was collected by the German church historian Hermann Goltz, who installed the 'Johannes Lepsius Archive' in Halle upon Saale with Martin Luther University of Halle-Wittenberg.