Georg Hans Emmo Wolfgang Hieronymus (1846–1921) was a European botanist of German extraction.

He began his career as a medical student in Zürich and Bern from 1868 to 1870, but became interested in botany, instead.

While in South America, he investigated flora native to Argentina, Bolivia, Brazil and Uruguay.

In the same year he started to edit the exsiccata series Herbarium cecidiologicum together with Ferdinand Albin Pax.

He was known for his plant collections in both central Europe and in much of South America.