The share of boys and men among detected victims of human trafficking is increasing globally, yet there is limited evidence on the specific experiences of these populations. The knowledge gap on mental health outcomes and support needs is particularly salient, which is problematic given the importance of psychological and emotional stabilisation in promoting recovery and avoiding re-victimisation. This systematic review reports on mental health outcomes identified in boys and young men who have experienced human trafficking. By describing the implications for services, the review seeks to identify challenges and opportunities in accessing and delivering mental health care and support to this population in post-trafficking settings. The review includes 31 papers published in English after 2000 and identified through database and grey literature searches. Despite significant limitations, such as a lack of gender-disaggregated results and imbalanced sample composition, which limit the possibility of extracting male-specific findings, the review highlights several mental health symptoms commonly described in the literature (e.g., depression, anxiety, PTSD, lack of self-esteem, lack of self-control). Regarding mental health care support, the review further identifies challenges specific to boys and young men (e.g., poor identification as trafficking victims) and challenges that disproportionately impact this population (e.g., confidentiality concerns; reluctance to seek help; trust issues).