This chapter examines the relationship between social cohesion, multiculturalism, and peer violence in the school context. It is based on studies on social cohesion, highlighting its role in societal integration and its impact on school coexistence. The chapter addresses the challenges and paradoxes of social cohesion, such as inclusion/exclusion and forced solidarity, as well as its connection to student well-being. It also explores how multiculturalism influences social cohesion and school dynamics, emphasizing the importance of inclusive educational policies and dialogic learning strategies. Additionally, it examines the relationship between social cohesion and school violence, identifying how strengthening community ties reduces aggression and enhances student well-being. Finally, the chapter underscores the importance of education in fostering social cohesion as a pathway to well-being, emphasizing the role of teachers and school leaders in creating equitable and inclusive learning environments. This analysis provides a multilevel and multidimensional perspective on the significance of social cohesion in education and its role in shaping more united, collaborative, and peaceful societies.