Johann Tobias Mayer (5 May 1752 – 30 November 1830) was a German physicist.
He was mainly well known for his mathematics and natural science textbooks.
Anfangsgründe der Naturlehre zum Behuf der Vorlesungen über die Experimental-Physik, an 1801 physics text, was the most influential of its time in the German-speaking countries.
Mayer's research in experimental physics and astronomy appeared in Annalen der Physik.
He is not to be confused with his famous father, the astronomer Tobias Mayer.