Background: Self-harm among young people is a major public health concern, and whilst schools are well placed to identify and intervene with students who self-harm, the literature shows that school staff lack training and confidence in this area. This systematic review investigated the effectiveness, feasibility and acceptability of training interventions and support tools intended to equip school staff with skills and knowledge to adequately respond to students’ disclosure of self-harm. Method: References for this review were identified through systematic searches of Medline, Embase, PsycINFO, Child Development & Adolescent Studies, ERIC, ASSIA and British Education Index on with search terms “self-harm”, “training”, “school staff” and “young people”. Thematic synthesis was used to analyse qualitative data. Results: We found that all eight included studies evaluated interventions/tools that were highly effective in terms of an increase in knowledge, skills and confidence of staff in responding to self-harming youth. Acceptability was good with high levels of satisfaction and perceived benefit by staff, though data on feasibility of the interventions was lacking. Limitations of the studies included a paucity of follow-up data, and lack of data relating to student outcomes and actual changes in staff practice in schools. Conclusions: The findings from this review indicates that more evidence is needed to determine the effectiveness, acceptability and feasibility of interventions/tools for school staff addressing self-harm. Further studies should focus on maintaining knowledge, confidence and comfort levels over time, and determine the feasibility of interventions/tools with different staff cohorts and across school settings, as well as address outcomes for students.