Ernst Gustav Zaddach (7 June 1817, Danzig – 5 June 1881, Königsberg) was a German geologist and zoologist, who made contributions in the fields of carcinology and entomology.
He is also known for his investigations of amber found in Samland (Baltic coast).
From 1836 to 1841 he studied sciences at the universities of Berlin and Bonn and later taught classes in natural history at the Collegium Fridericianum in Königsberg.
[1] In 1862, he was appointed director of the zoological museum in Königsberg.
[2] The amphipod species Gammarus zaddachi (Sexton, 1912) is named after him.