This paper describes the results of a rapid evidence assessment that aimed to identify the characteristics and efficacy of interventions that aimed to or reportedly changed personal or social identity. Following a rapid but systematic search of the published, peer-reviewed research on identity change, 400 studies or reviews were screened for eligibility for inclusion in the review, and 22 were retained. The interventions and samples were diverse and studies came from a broad geographic area. The quality of the research varied, but the majority was assessed as carrying a low weight of evidence. Just under two-thirds of the studies were qualitative, and most explored, retrospectively, participants’ perceptions of, or applied theoretical frameworks to, identity change some time after an intervention. Quantitative studies provided little evidence of the effectiveness of interventions in changing identity. Qualitative studies most commonly applied and then supported the Social Identity Theory of Identity Change to explain perceived changes in identity. Implications for research are discussed.