John Lewis Selfridge (February 17, 1927 – October 31, 2010), was an American mathematician who contributed to the fields of analytic number theory, computational number theory, and combinatorics. Selfridge received his Ph.D. in 1958 from the University of California, Los Angeles under the supervision of Theodore Motzkin. In 1964, Selfridge and Alexander Hurwitz proved that the 14th Fermat number was composite.However, their proof did not provide a factor. It was not until 2010 that the first factor of the 14th Fermat number was found.