Educators remove over 3.45 million students from school annually for disciplinary reasons, despite strong evidence that school suspension policies are harmful to students. The research presented in this volume demonstrates that disciplinary policies and practices that schools control directly exacerbate todays profound inequities in educational opportunity and outcomes. Part I explores how suspensions flow along the lines of race, gender, and disability status. Part II examines potential remedies that show great promise, including a district-wide approach in Cleveland, Ohio, aimed at social and emotional learning strategies. Closing the School Discipline Gap is a call for action that focuses on an area in which public schools can and should make powerful improvements, in a relatively short period of time.