BackgroundSelf-harm is a major public health concern with evidence suggesting that the rates are higher in the United Kingdom than anywhere else in Europe. Increasingly, policy highlights the role of school staff in supporting young people (YP) who are self-harming, yet research indicates that school staff often feel ill-equipped to provide support and address self-harm behaviors. Here, we assess the impact of a bespoke eLearning module for United Kingdom secondary school teachers on teacher’s actual and perceived knowledge of self-harm, and their self-reported confidence in supporting and talking to YP who self-harm.MethodsTwenty-one secondary schools across the West Midlands and South East of England were invited to complete a 30-min web-based eLearning module on self-harm in schools. Participants completed pre-and post-intervention measures.ResultsOne-hundred and seventy-three teachers completed the eLearning, and pre-and post-measures. The eLearning significantly enhanced participants’ perceived knowledge, actual knowledge, and confidence in talking to and supporting YP who self-harm. The majority of participants (90.7%) felt that eLearning was a good way to receive training.ConclusionThe 30-min eLearning module was rated highly and may be an effective way to increase secondary school teachers’ knowledge of self-harm, and confidence in supporting and talking to YP who self-harm.