Werner-Seidler, AlizaCorkish, BrittanyTickell, AshleighFogarty, AndreaKafer, KristineBatterham, Philip J.Torok, MichelleO’Dea, Bridianne2026-06-082026-06-080311-6999https://hdl.handle.net/1885/733810098The rate of suicidality and self-harm in adolescents has risen sharply over the last decade. Adolescents with suicidal thoughts and self-harming behaviours frequently present to school counsellors, yet many counsellors report feeling ill-equipped to support these students. The purpose of the current study was to evaluate the effects of a face-to-face training program developed specifically for school counsellors that aimed to improve their knowledge and confidence in supporting students who self-harm and/or have thoughts of suicide. Participants were 389 school counsellors working in secondary schools in New South Wales, Australia. Participants completed a one-day training session delivered in person by the Black Dog Institute. Evaluation measures were assessed pre-training, immediately post-training and three-months later (follow-up). There was an improvement in counsellor knowledge and confidence at post-training and follow-up (d = 0.50–0.77). Participants reported high levels of training acceptability, with over 90% rating the quality of the training as ‘very good’ or ‘excellent’. Limitations of the study include the lack of a control group, the inclusion of counsellors from government schools only, and the use of a retrospective consent process. Overall, results suggest this training may improve counsellor knowledge and confidence in supporting student suicidality and/or self-harm.Open Access funding enabled and organized by CAUL and its Member Institutions. AW-S is supported by an NHMRC Investigator Grant Fellowship (1197074).14enPublisher Copyright: © The Author(s) 2025.Professional developmentPsychologySelf-harmSuicidality202510.1007/s13384-025-00917-2105018763374