Franz Dannehl (7 February 1870, Rudolstadt – 1947) was a German entomologist who specialised in Lepidoptera.
He was an insect dealer first in Bözen, then in Munich.
His private collection, mainly butterflies and moths from the German Tyrol is in Museo Civico di Zoologia, Rome, Zoologische Staatssammlung München in Munich and Museum für Naturkunde in Berlin.
According to historian Peter Levenda, Dannehl was a member of the occultist Thule Society, and joined the Nazi Party early on.