John Marks Templeton, Jr. (born February 19, 1940 in New York City) is the elder son of the stock investor, businessman and philanthropist John Templeton and serves as the Chairman and President of the John Templeton Foundation.
Templeton graduated from Yale University, where he was a member of Elihu senior society, as was his father. He later earned a medical degree at Harvard Medical School, and then served as a physician in the U.S. Navy. In 1977, he went to work at the Children's Hospital of Philadelphia as a pediatric surgeon and trauma program director. He retired in 1995 to become head of the John Templeton Foundation.
Templeton is an evangelical Christian.
In 2008, Templeton donated $450,000 to the National Organization for Marriage.
In 2010, Politics Magazine named him one of the most influential Republicans in Pennsylvania.