Granville Stanley Hall (February 1, 1844 in Ashfield, Massachusetts - April 24, 1924) was a psychologist and educationalist who pioneered American psychology. Hall was the first president of the American Psychological Association and also the first president of Clark University (1888 - 1920).

Hall graduated from Williams College in 1867, but also studied at the Union Theological Seminary and Harvard University. His career began when he taught English and philosophy at Antioch College in Ohio. Then, from 1882-88, he taught psychology at John Hopkins University. While there, Hall objected vehemently to the emphasis on teaching subjects such as Latin, mathematics, science and history, saying instead that high school should be more focused on the education of adolescents than on preparing students for college.

In 1887, he founded the American Journal of Psychology and was named president of Clark University in 1889. In this role, Hall was instrumental in the development of educational psychology and he tried to show the effect adolescence has on education.

Hall was also influenced by Darwin's Theory of Evolution. This prompted him to undertake scientific examination of child development in order to learn about the inheritance of behaviour. However, these studies were subjective, making validation impossible.

Hall's major works were Adolescence and Aspects of Child Life and Education.