Inclusive education of pupils with special educational needs (SEN) has become a global trend. However, a considerable number of studies have shown that mere enrolment in mainstream classrooms is not enough to support the social participation of pupils with SEN. These children are at risk of experiencing difficulties in their involvement with peers at school. Thus, the question arises of how social participation can be fostered in mainstream classrooms. A systematic review of 35 studies was conducted to investigate which interventions are effective in inclusive mainstream preschool and elementary classrooms. Teaching interaction strategies to typically developing pupils, group activities in the academic context (cooperative learning and peer-tutoring), support groups for pupils with SEN, and training paraprofessionals to facilitate social interactions, were found to improve the social participation of pupils with SEN in general education classrooms. Nevertheless, there is need for more intervention studies implementing a variety of strategies and including different groups of pupils with SEN.