Gideon Jan (Don) Mellenbergh (9 August 1938 – 27 March 2021) was a Dutch psychologist, who was Professor of Psychological methods at the University of Amsterdam, known for his contribution in the field of psychometrics,[2][3] and Social Research Methodology.

Born and raised in Amsterdam, Mellenbergh received his MA in psychology from the University of Amsterdam in 1965, and his PhD in psychology in 1971 under the supervision of Professor Adriaan de Groot with a dissertation about educational tests, entitled "Studies in studietoetsen" (Studies on educational tests).

[4] At the University of Amsterdam, Mellenbergh began his academic career as an assistant professor of psychological methods in 1965.

Late 1969 he was visiting research assistant at the University of Chicago, studying educational methods.

[4] Mellenbergh performed many administrative functions in Dutch research institutes, is member of the Royal Netherlands Academy of Arts and Sciences (KNAW) since 1993,[5] the Psychometric Society, the American Psychological Association (APA), the International Statistical Institute (ISI), and the Interuniversity Graduate School of Psychometrics and Sociometrics (IOPS).