Joseph F. Fraumeni Jr. (born April 1, 1933) is an American physician and cancer researcher.

He completed his medical residency at Johns Hopkins Hospital and Memorial Sloan Kettering Cancer Center.

He stepped down from this position in 2012 to become a senior investigator and advisor to the National Cancer Institute.

One of Fraumeni's research accomplishments was the identification in 1969 with Frederick Pei Li of four families with an increased susceptibility to multiple forms of cancer in children and young adults.

[4] Fraumeni has been recognized by numerous honors and awards for his research into the genetic and environmental determinants of cancer.