The authors investigated a combined social and emotional learning and mindfulness-based intervention as delivered by school counselors to students in classrooms and their teachers using consultation practices. The study used a cluster-randomized design at the classroom level, with an ethnically diverse sample of 109 middle school students divided between treatment and delayed treatment groups. Analyses found significant intervention effects for the treatment group in students' changes in stress tolerance, social curiosity, executive functioning (i.e., shift, plan and organize, and task monitoring), and academic achievement (i.e., mathematics, science, English, and social studies). Implications of these findings evince how theory-informed school counseling can contribute to important outcomes in educational settings.