The psychological consequences of child sexual abuse on children’s mental health and emotional well-being are well documented, and the importance of safeguarding training for professionals working with children and young people unequivocal. Effective support for children who have been sexually abused online is essential to enable them to progress towards recovery. Yet many professionals feel they lack knowledge and understanding of how best to work with children who have been sexually abused online. This study therefore evaluates the outcomes of a short inter-professional training course designed to develop professionals’ competence and confidence when responding to the needs of children and their families after online sexual abuse. Participants (n = 114) were recruited on a voluntary basis from a range of professional backgrounds, including some teaching and social work students in England, Wales and Northern Ireland. The questionnaire collected both quantitative and qualitative data. There were consistent, statistically significant improvements in the professionals’ views on their knowledge of the subject, their ability to assess online risk and their confidence levels after completing the training course. The feedback from the participants suggested that the learning tools adopted in the training were highly appropriate and that the inter-professional delivery was a key aspect to the positive learning experience. This study suggests that multidisciplinary training, combined with real-life case studies, can be highly effective in improving knowledge and understanding of online Child Sexual Exploitation and Abuse (CSEA), thereby improving professionals’ confidence in supporting children, young people and their families. The need for and the importance of inter-professional training are highlighted.