The following is a list of mental disorders as defined by the DSM and ICD.

The Diagnostic and Statistical Manual of Mental Disorders (DSM) is the American Psychiatric Association's standard reference for psychiatry which includes over 400 different definitions of mental disorders. The International Statistical Classification of Diseases and Related Health Problems (ICD) is published by the World Health Organization, and it contains a section on psychological and behavioral disorders. The diagnostic criteria and information in the DSM and ICD are revised and updated with each new version. This list contains conditions currently recognised descriptions of mental disorders as defined by these two documents.

There is disagreement in various fields of mental health care, including the field of psychiatry, over the definitions and criteria used to delineate various disorders. Of particular concern to some professionals is whether some of these conditions should be classified as 'mental illnesses' at all, or whether they would be better described as neurological disorders, or in other ways. Some items listed are ultimately removed: homosexuality was originally listed in the DSM, but was removed when the American Psychiatric Association officially stated that "homosexuality per se implies no impairment in judgment, stability, reliability, or general social or vocational capabilities".