John E. Carlstrom (born 1957) is an American astrophysicist, and Professor, Departments of Astronomy and Astrophysics, and Physics, at the University of Chicago.
He graduated from Vassar College with a B.A. in 1981, and from the University of California, Berkeley with a Ph.D. in 1988.
Carlstrom specializes in measurements of the Cosmic Microwave Background, and has led several experiments including the Degree Angular Scale Interferometer, the Sunyaev-Zel'dovich Array, and the South Pole Telescope.