School bullying is a serious social problem, which has received widespread public, media, and research attention over the years. The first study of bullying was published in 1969 by a school physician named P. P. Heinemann (Olweus, 1999), which was subsequently followed by extensive empirical inquiry since the 1970s in Scandinavia led by Dan Olweus (Vaillancourt et al., 2008). In subsequent decades, social scientists have developed a rich theoretical and empirical body of knowledge with regards to children and adolescents’ experiences in bullying. Scholars conceptualise bullying as a sub-category of aggression (Smith et al., 2002), characterised as being purposeful, including an imbalance of power, and being repetitive (Hunter, Boyle & Warden, 2007; Smith, 2014). Bullying has for the most part been explored from a psychological perspective, providing insights into proximal risk factors, such as individual traits and behaviours. However, bullying is a complex, multifaceted problem, and consideration of theoretical frameworks from outside psychology is necessary to fully explain why certain individuals (or groups of individuals) are involved in bullying. Scholars have therefore come to realise the importance of integrating psychological theories with social environmental perspectives (sociological, anthropological, political-economic; Lawson & King, 2012). This has the potential to broaden perspectives on the etiology and outcomes of bullying, introduce innovative methodologies, and raise important questions about new approaches to prevention and intervention (Holt et al., 2017).This chapter will provide an overview of multiple social science theories and perspectives in explaining bullying. It is divided by theories and perspectives represented by four major branches of social science: psychology, sociology, anthropology, and political-economics.