Hans Friedrich Gadow (8 March 1855 - 16 May 1928) was a German ornithologist.
Gadow was born in Pomerania, the son of an inspector of the Prussian royal forests. He studied at the universities of Berlin, Jena and Heidelberg. At Jena he studied under Ernst Haeckel and at Heidelberg under the anatomist Karl Gegenbaur. After graduation he travelled to the Natural History Museum in London at the request of Albert Günther, to work on the Museum's Catalogue of Birds. Gadow prepared volume VIII on the Titmice, Shrikes and Nuthatches, and volume IX on the Sunbirds and Honeyeaters.
In 1884 Gadow succeeded Osbert Salvin as Curator of the Strickland Collection at Cambridge University, as well as being appointed Lecturer on the Morphology of Vertebrates. He became a member of the British Ornithologists' Union in 1881 and a fellow of the Royal Society in 1892. He married Clara Maud Paget, daughter of Sir George E. Paget.
Gadow's publications included Classification of the Vertebra (1898), a translation of Haeckel's work entitled The Last Link (1898) and the articles on anatomy in Alfred Newton's Dictionary of Birds.