Sexology is the systematic study of human sexuality. Modern sexology is a multidisciplinary field which uses the techniques of fields including biology, medicine, psychology, statistics, epidemiology, pedagogy, sociology, anthropology, and sometimes criminology to bear on its subject.

It studies human sexual development and the development of sexual relationships as well as the mechanics of sexual intercourse and sexual dysfunction. Sexology encompasses all aspects of sexuality, including attempting to characterise "normal sexuality" and its variants. It also documents the sexuality of special groups, such people with a disability, children, and older adults, and studies sexual pathologies such as sex addiction and child sexual abuse.

Sexology is considered descriptive, not prescriptive: it attempts to document reality, not to prescribe what behavior is suitable, ethical, or moral.