James Bryant Conant (March 26, 1893 - February 11, 1978) was a chemist, educational administrator, and public servant. He was born in Dorchester, Massachusetts in 1893 and went on to study chemistry at Harvard (B.A., 1914; Ph.D., 1917). As a Harvard professor, he worked on both physical and organic chemistry.

In 1933, Conant accepted an appointment as the President of Harvard University, a post he held until 1953. Between 1941 and 1946, he also served as chairman of the National Defense Research Committee, a position from which he played a key role in ramping up of the Manhattan Project which developed the first nuclear weapons. After World War II he was an advisor to both the National Science Foundation and the Atomic Energy Commission. He served as US High Commissioner and Ambassador to Germany from 1953 to 1957.

As the university's president, Conant was instrumental in transforming Harvard, until then widely perceived as a 'finishing school' for members of the New England upper class, into a world-class research university. He introduced aptitude tests into the undergraduate admissions system so that students would be chosen for their intellectual promise and merit, rather than their social connections. Many American colleges followed Conant's lead, and this campaign led eventually to the creation of the SAT. Conant also did much to move general undergraduate curriculum away from its traditional emphasis on the classics, and towards a more scientific and modern subject matter. He was active throughout his career on issues of education and scientific policy.

Conant died in Hanover, New Hampshire in 1978.