Charles Weissmann (born 14 October 1931, Budapest, Hungary) is a Hungarian-born Swiss molecular biologist.
Weissmann went to Zurich University and obtained his MD in 1956 and Ph. D. in Organic Chemistry in 1961. Weissmann was director of the Institute for Molecular Biology in Zurich, President of the Roche Research Foundation and co-founder and Member of the Scientific Council of Biogen. He is currently Chairman of the Department of Infectology, Scripps Florida.
Weissmann won several awards and is a member of the American Society of Biological Chemistry and the Deutsche Akademie der Naturforscher Leopoldina. He also became a Foreign Associate of the U.S. National Academy of Sciences, the Royal Society (UK) and the Orden Pour le Merite (Germany).
Weissmann is particularly known for the first cloning and expression of interferon and his contributions to the unraveling of the molecular genetics of neurogenerative prion diseases such as scrapie, Creutzfeldt-Jacob disease and "mad cow" disease.
In 1978, Weissmann co-founded the biotech company Biogen in Geneva. Biogen is considered one of the pioneers of the biotechnology industries.