OBJECTIVE: Empowerment is critical for cancer patients to make informed choices, to manage medication, and to navigate through the oncological care system. Cancer peer support provides patients with information, emotional relief and may promote empowerment. This paper provides a systematic review of the literature examining the impact of cancer peer support interventions on psychological empowerment. METHODS: PubMed, Web of Science, CINAHL, Cochrane Library, PsycINFO and PSYNDEX databases were systematically searched from inception until December 2020. We included quantitative studies, published in English or German, which examined peer-led cancer support interventions and their impact on the three components of psychological empowerment (intrapersonal, interactional and behavioural) among participating cancer patients. RESULTS: Database searches and screening of relevant reference lists identified 2336 potentially relevant articles. A total of 29 studies were included in the review. Active coping, self-efficacy and knowledge were the most prominent dimensions of empowerment in these studies. The majority of studies revealed that peer support led to a small to medium, significant increase in psychological empowerment, and was associated with further patient-reported benefits. CONCLUSIONS: The existing evidence suggests a weak to moderate, positive association between cancer peer support and the three components of psychological empowerment among cancer patients. Peer support groups should be seen as an important element in cancer care and clinical practice and, thus, be more systematically involved in cancer care.