团体心理治疗被定义为一种创建于特殊关系的谈话治疗。顾名思义，团体（心理）治疗就是一群特定人们与治疗师透过谈话达成治疗目标的一种心理治疗，英文称作group psychotherapy。

在美国最早有en:Joseph H. Pratt、en:Trigant Burrow和en:Paul Shilder这些人提出团体治疗。1920年代，en:Jacob L. Moreno在心理剧发展过程中首度提到团体治疗一词。之后佛洛伊德在团体心理学与Ego的分析(en:Group psychology and the Analysis of Ego)书中，思索群体行为的意义以及团体和领导者的关系。但对近代影响较深远的，则是en:Samuel Slavson、en:Hyman Spotnitz和en:Irvin Yalom（台湾翻译：欧文·亚隆）。

Group psychotherapy or group therapy is a form of psychotherapy in which one or more therapists treat a small group of clients together as a group. The term can legitimately refer to any form of psychotherapy when delivered in a group format, including Cognitive behavioural therapy or Interpersonal therapy, but it is usually applied to psychodynamic group therapy where the group context and group process is explicitly utilised as a mechanism of change by developing, exploring and examining interpersonal relationships within the group.