Samuel J. Messick III (3 April 1931 – 6 October 1998) was an American psychologist professor whose work at the Educational Testing Service examined construct validity.
Messick influenced language testing in 2 main ways: in proposing a new understanding of how inferences made based on tests must be challenged, and in drawing attention to the consequences of test use.
Division 5 of the American Psychological Association named the annual Samuel J. Messick Distinguished Scientific Contributions Award in his honor. One of his collaborators, Douglas N. Jackson, won the award in 2004.