Michael S. Turner (born July 29, 1949)[1] is an American theoretical cosmologist who coined the term dark energy in 1998.

[1] Turner's book The Early Universe, co-written with fellow Chicago cosmologist Edward Kolb, is a standard text on the subject.

[8] In 2022, Turner was appointed as a co-leader, with Maria Spiropulu, of a National Academies of Science, Engineering and Medicine study, leading a committee of 17 physicists world-wide to consider the strategic vision of research in elementary particle physics.

He was a visiting professor at the Institute for Theoretical Physics at the University of California, Santa Barbara from 1981 to 1982, and became a scientist at the Fermi National Accelerator Laboratory in Batavia, Ill, in 1983.

He served as chair of the department from 1997 to 2003, and was named the Bruce V. and Diana M. Rauner Distinguished Service Professor of Astronomy and Astrophysics in 1998.