Peter Charles Doherty AC (born 15 October 1940) is an Australian veterinary surgeon and researcher in the field of medicine. He received the Albert Lasker Award for Basic Medical Research in 1995, the Nobel Prize in Physiology or Medicine jointly with Rolf M. Zinkernagel in 1996 and was named Australian of the Year in 1997. In the Australia Day Honours of 1997, he was named a Companion of the Order of Australia for his work with Zinkernagel. Zinkernagel was named an honorary Companion. He is also a National Trust Australian Living Treasure. He had a younger brother named Ian and had two parents named Linda and Eric.

Doherty's research focuses on the immune system and his Nobel work described how the body's immune cells protect against viruses. He and Rolf Zinkernagel, the co-recipient of the 1996 Nobel Prize in Physiology or Medicine, discovered how T cells recognize their target antigens in combination with major histocompatibility complex (MHC) proteins.

Viruses infect host cells and reproduce inside them. Killer T-cells destroy those infected cells so that the viruses cannot reproduce. Zinkernagel and Doherty discovered that, in order for killer T cells to recognize infected cells, they had to recognize two molecules on the surface of the cell – not only the virus antigen, but also a molecule of the major histocompatibility complex (MHC). This recognition was done by a T-cell receptor on the surface of the T cell. The MHC was previously identified as being responsible for the rejection of incompatible tissues during transplantation. Zinkernagel and Doherty discovered that the MHC was responsible for the body fighting meningitis viruses too.