James Peebles is a Canadian-born American physicist who was awarded the 2019 Nobel Prize for Physics for his work on physical cosmology. He received one half of the prize; the other half was awarded to Swiss astronomers Michel Mayor and Didier Queloz.

Peebles received a bachelor’s degree in 1958 from the University of Manitoba and a doctorate in 1962 from Princeton University. He remained at Princeton for the remainder of his career, becoming an assistant professor in 1965 and a full professor in 1972. He became the Albert Einstein Professor of Science in 1984 and a professor emeritus in 2000.