James William Colbert Jr. (December 15, 1920 – September 11, 1974) was an American physician-scientist and immunologist. He was a professor of medicine at Yale University from 1949 to 1953, the dean of the Saint Louis University School of Medicine from from 1953 to 1961, then a director and academic at the National Institute of Allergy and Infectious Diseases and the Medical University of South Carolina.
After graduating from the College of the Holy Cross, Colbert earned his medical degree from Columbia University with a research specialty in infectious diseases. During the late 1940s and early 1950s, he conducted research on viral hepatitis with the United States Army Medical Corps before becoming a professor at the Yale School of Medicine. In 1953, at age 32, he was named dean of the Saint Louis University School of Medicine, becoming the youngest dean of a medical school in the country.
Colbert had eleven children, including comedian Stephen Colbert and politician Elizabeth Colbert Busch. He was killed, along with two of his sons, in the crash of Eastern Air Lines Flight 212 near Charlotte, North Carolina, in 1974. At the time of his death, he was the vice president of medical affairs at the Medical University of South Carolina.