Objective: Informal caregivers of cancer patients often experience significant physical and psychological burdens, impacting their quality of life (QoL). These challenges are intensified for caregivers from rural, LGBTQIA+, culturally diverse, and Indigenous communities due to cultural, linguistic, and systemic barriers to appropriate and responsive support. This study evaluated the feasibility, acceptability, and effectiveness of psychosocial interventions in reducing burden, distress, and anxiety, while improving QoL among caregivers from these priority populations. Method: A systematic search of five databases was conducted to identify peer-reviewed studies published in English between 2014 and 2024. Quantitative studies focusing on psychosocial interventions for adult cancer carers from at least one priority group were included. Commentaries, protocols, and grey literature were excluded. The Joanna Briggs Institute critical appraisal tools were used to assess the quality. Results: After screening 5,171 titles and abstracts, 26 articles underwent full-text review, and two articles were included in the review. Studies focused on carers of people with advanced cancer; one among rural carers, the other among Latinx carers. The rural study involved a pilot RCT (N=63) delivering six weekly coaching sessions via lay navigators, addressing self-care, stress, and advanced care planning. The intervention demonstrated high acceptability, with 65% session adherence and 9.4/10 participant satisfaction. The second study evaluated the acceptability of a planned intervention for Latinx carers (N=14). The intervention included meaning-centred psychotherapy and couples communication skills training. Acceptability ratings were high, ranging from 78.6% to 100%. Conclusion and Clinical Implications: There is a notable lack of studies evaluating supportive care interventions for cancer carers from priority populations. No interventions were identified for LGBTQIA+ or Indigenous caregivers, highlighting a critical gap. To promote equitable caregiver support and reduce disparities in cancer care, future research must prioritise the development and evaluation of tailored interventions for caregivers from diverse and underserved populations.