Ernst Hänßler was born in Steinen on January 23, 1848, the son of Anna Magdalena Hänßler and Johann Matthias Hänßler. He decided to become a painter like his father. He developed his artistic talent at the School of Arts and Crafts in Freiburg and later at the Grand Ducal-Baden School of Art in Karlsruhe.

He was an assistant to a decorative painter in Baden-Baden before volunteering for military service with the Fourth Baden Infantry Regiment Prince William No. 112, with which he took part in the Franco-Prussian War of 1870/71.