Trossingen (Swabian: Drossinge) is a town in Baden-Württemberg, Germany.

It is situated in a region called Baar, between the Swabian Alb and the Black Forest.

In 1830 Christian Messner [de] from Trossingen, a cloth maker and weaver, copied a harmonica brought to Trossingen by his next door neighbor, a clockmaker from Vienna.

Trossingen is not the home of the world's oldest existent harmonica manufacturer, C.A.

At the edge of town, in a former clay quarry, were found several dozen skeletons, both complete and partial, of the prosauropod dinosaur Plateosaurus engelhardti during excavations in the early 20th century.