Johann Gottlob Lehmann (4 August 1719 - 22 January 1767) was a German mineralogist and geologist noted for the development of stratigraphy.

He attended the University of Wittenberg, from which he received an M.D. in 1741, and then established a practice in Dresden. Living in Saxony, he developed an interest in the local mining industry, and published on the chemical composition of ore deposits. In 1750 the Royal Prussian Academy of Sciences commissioned him to study mining practices throughout Prussia.

In 1761 the Imperial Academy of Sciences invited him to St Petersburg, where he became professor of chemistry.