AbstractAim: There is increasing awareness of the prevalence of mental health disorders in children in the UK, but research on the efficacy of interventions meeting this need is limited. This study assessed whether The Place2Be model of individual and group intervention has a positive influence on children's social and emotional wellbeing. Providing emotional and therapeutic support to school age children in England and Scotland, The Place2Be delivers school‐based therapeutic interventions to around 47,000 children in 143 primary schools, two secondary schools and one independent school. Method: Strengths and Difficulties Questionnaire data was collected from a national sample of primary school children aged 4–11 (N=1,864) both before and after accessing an individual (n =1,645) or group (n =215) intervention. Results: Repeated measures t‐tests revealed that children had significantly lower Total Difficulties scores post‐intervention than pre‐intervention as rated by their class teachers and parents (Teacher‐rated: p<0.001, d = 0.39; Parent‐rated: p<0.001, d = 0.47). Children also had significantly higher Prosocial scores post‐intervention (Teacher‐rated: p<0.001, d = 0.25; Parent‐rated: p<0.001, d = 0.15). Conclusions: Children's social and emotional behaviour, as perceived by their teachers and parents, was improved following therapeutic intervention with The Place2Be. These findings have important implications for service providers looking to commission projects for the benefit of their local community.