Renato Dulbecco (born February 22, 1914) is an Italian virologist who won a 1975 Nobel Prize in Physiology or Medicine for his work on reverse transcriptase.

In 1973 he was awarded the Louisa Gross Horwitz Prize from Columbia University together with Theodore Puck and Harry Eagle. Dulbecco was the recipient of the Selman A. Waksman Award in Microbiology from the National Academy of Sciences in 1974.

Renato Dulbecco developed a viable technique for growing viruses in lab cultures, showed how the polyoma virus, which causes many animal cancers, infects cells, and shed great insight on how cells are infected by viruses.

He worked with Rita Levi-Montalcini at the University of Turin, Salvador Luria, Hermann J. Muller, and James Watson at Indiana, and Max Delbrück at Cal-Tech. He shared the 1975 Nobel Prize for Medicine with David Baltimore and Howard M. Temin, both of whom had been his students.

Dulbecco and his group demonstrated that the infection of normal cells with certain types of viruses (oncoviruses) led to the incorporation of virus-derived genes into the host-cell genome, and that this event lead to the transformation (the acquisition of a tumor phenotype) of those cells. As demonstrated by Temin and Baltimore, who shared the Nobel Prize with Dulbecco, the transfer of viral genes to the cell is mediated by an enzyme called reverse transcriptase (or, more precisely, RNA-dependent DNA polymerase), which replicates the viral genome (in this case made of RNA) into DNA, which is later incorporated in the host genome.

Oncoviruses are the cause of some forms of human cancers. Dulbecco's study gave a basis for precise understanding of the molecular mechanisms by which they propagate, thus allowing us to better fight them. Furthermore, the mechanisms of carcinogenesis mediated by oncoviruses closely resemble the process by which normal cells degenerate into cancer cells. Dulbecco's discoveries allowed us to better understand and fight cancer.

Author of books:
-Virology (1980, with Harold S. Ginsberg)
-The Design of Life (1987)
-Encyclopedia of Human Biology (1991, editor)