Johann Bartholomew (Bartholomäus) Trommsdorff (8 May 1770, Erfurt – 8 March 1837), was a German chemist and pharmacist noted for his 1805 Systematisches Handbuch der Gesammten Chemie (Systematic Handbook of the Whole of Chemistry); a work that was published in eight volumes.
He was the son of Wilhelm Bernhard Trommsdorff (1738–1782), a pharmacist and a chemistry teacher at the University of Erfurt. His father died when he was twelve, causing the family financial difficulties. In 1784 Johann began work as an apprentice-pharmacist at the Hofapotheke in Weimar under his father's friend Wilhelm Heinrich Sebastian Bucholz and Johann Friedrich August Göttling. From 1788 he furthered his education in Stettin and Stargard, returning to Erfurt in 1790, where he took charge of his late father's pharmacy, the Schwanen-Ring-Apotheke.
In 1795 he became an associate professor at the University of Erfurt, where he gave lectures in chemistry, mineralogy and pharmacy-dispensary (Rezeptierkunst). Shortly afterwards he founded the Chemisch-physikalisch-pharmaceutische Pensionsanstalt für Jünglinge, an establishment that is considered to be the first pharmaceutical institute in Germany. At the institute, prospective pharmacists were trained in physics, chemistry and pharmacy, and also given instruction in the fields of botany, zoology, mineralogy, mathematics and natural philosophy. More than 300 students attended between 1795 and 1828, helping to train an entire generation of chemical pharmacologists for the German drug industry.