This chapter reviews the conceptualization and definitions of school climate and examines evidence regarding its correlates and consequences. The review indicates that there are multiple ambiguities in current conceptualizations of climate. The roles of school violence, bullying, and safety are not consistent across definitions. Most definitions focus on climate as it relates to individuals. Far less attention has focused on the school as whole, overlooking to a large extent school level issues, including school subcontexts that have particular subclimates (e.g. “unowned spaces”). The role of the district is also sorely missing. It discusses the importance of conceptualizing and measuring multiple perspectives on school climate, both on the individual and school level. The chapter presents a cross-lagged study of the relationships between school climate, violence, and academic achievement over time in a large and representative study of all schools in California. Finally, the chapter discusses climate improvement programs, interventions, and practices.