This chapter provides an overview of generalized anxiety disorder (GAD) in children and adolescents as applied to the school setting. GAD is diagnosed frequently in adults and is one of the most common disorders among children and adolescents. It is characterized by excessive worry that can be about many things, and, in children, it is somewhat common to be connected to school performance. This chapter focuses on GAD as it pertains to school psychologists with regard to criteria from both the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition; DSM-5) and the Individuals with Disabilities Education Improvement Act (IDEA). Cultural issues related to etiology, identification, and treatment are also addressed. The chapter addresses functioning and quality-of-life issues for individuals with GAD across childhood and adolescence. Implications for school psychologists and their role in assessment and intervention implementation are discussed.