Students who demonstrate conduct problems pose ongoing challenges for teachers. Therefore, prevention programs that all families and teachers of young children can use to promote social and emotional learning, emotion regulation, and problem solving are of great interest to researchers and practitioners alike. This article describes the Incredible Years® programs for children and teachers and international findings regarding its implementation. The authors describe how these evidence-based programs for teachers and children were introduced and evaluated in Wales and how the demonstration of effectiveness has resulted in a subsequent roll out that has been supported by local authorities and the Welsh Government.