Robert Hartig (born: Heinrich Julius Adolph Robert Hartig, 30 May 1839, in Braunschweig – died 9 October 1901, in Munich) was a German forestry scientist and mycologist.

He was educated at the Collegium Carolinum of Braunschweig, and at Berlin.

Hartig made significant contributions to knowledge of vegetable pathology.

Prior to his investigations on the progressive stages of disease in trees, little or nothing had been done in this area, so that Hartig may be considered the founder of arboreal pathology.

[1] Hartig worked in Eberswalde (1867–1878) and Munich (1878–1901), mainly in forest pathology.