Giovanna Tosato (born c. 1949) is an Italian–American physician-scientist and cancer researcher investigating the endothelium, angiogenesis, and the hematopoietic stem cell niche. She heads the molecular and cell biology section in the laboratory of cellular oncology at the National Cancer Institute in the United States. Tosato was a division director in the Center for Biologics Evaluation and Research from 1992 to 1999.