Paraphilia (previously known as sexual perversion and sexual deviation) is the experience of intense sexual arousal to atypical objects, situations, fantasies, behaviors, or individuals. It has also been defined as sexual interest in anything other than a consenting human partner.

There is no scientific consensus for any precise border between unusual sexual interests and paraphilic ones. There is an ongoing debate over which, if any, of the paraphilias should be listed in diagnostic manuals, such as the Diagnostic and Statistical Manual of Mental Disorders (DSM) or the International Classification of Diseases (ICD).

The number and taxonomy of paraphilia is under debate; one source lists as many as 549 types of paraphilia. The DSM-5 has specific listings for eight paraphilic disorders. Several sub-classifications of the paraphilias have been proposed, and some argue that a fully dimensional, spectrum or complaint-oriented approach would better reflect the evidence.