John Clements Collins (b. 1949) is a British-born American theoretical physicist and professor of physics at Pennsylvania State University. He attended the University of Cambridge where he obtained a B.A. in mathematics 1971 and a Ph.D. in theoretical physics in 1975. He worked as a postdoc and assistant professor from 1975 to 1980 at Princeton University. Collins was part of the faculty of the Illinois Institute of Technology from 1980 to 1990.