[3] He studied Theology at Königsberg and then became a teacher at the Ritterakademie ("Cathedral School"; literally "Knights' Academy") at Brandenburg an der Havel.

Hermes has become known, above all, for his novels "Geschichte der Miss Fanny Wilkes" ("The Story of Miss Fanny Wilkes" 1766)[4] and "Sophiens Reise von Memel nach Sachsen" ("Sophie's Journey from Memel to Saxony" 1769–1773 in five volumes)[5] which were very successful at the time, and translated into several languages.

The author gained the popular soubriquet "Sophien-Hermes" from it: its continuing importance two centuries later is based on its real-life descriptions concerning the cultural history of its time.

In 1779 he published in a stand-alone volume the poems from "Sophie's Journey", presented as songs and arias, with music by Johann Adam Hiller.

Other composers who set poems by Johann Timotheus Hermes to music were Maria Theresia von Paradis, Joseph Martin Kraus, Franz Anton Hoffmeister and Wolfgang Amadeus Mozart.