Gustav Behrend (January 10, 1847 – 1925) was a German dermatologist who was a native of Neustettin (today- Szczecinek, Poland).
In 1870 he received his medical doctorate at the University of Berlin, and during the Franco-Prussian War, he served as an assistant at the Reserve Lazareth in Berlin. In 1882 he became a lecturer at Berlin, and in 1891 was appointed chief physician at the Municipal Dispensary for Sexual Diseases. In 1897 he received the title of professor.
Behrend specialized in the fields of dermatology and syphilology, also dealing with the subject of prostitution. He was the author of numerous publications, including a well-regarded textbook on skin diseases, titled Lehrbuch der Hautkrankheiten (1883). He also contributed a number of articles to Albert Eulenburg's Real-Encyclopädie der gesamten Heilkunde.