This chapter provides an overview of school-based counseling, the approaches used throughout the book, and the special populations that are discussed in the later chapters. The chapter identifies a significant benefit of school-based counseling, which is that it often reaches young people who otherwise would not receive mental health services. It discusses strength-based counseling approaches that, instead of focusing on students’ psychopathology, promote resilience; these include solution-focused brief therapy and cognitive-behavioral therapy. Finally, it introduces the specific student populations that will be discussed in greater detail in the later chapters: students who are homeless, students living in foster care, students involved with the juvenile justice system, students who are LGBTQ, students who are pregnant or parenting, students who are gifted, students with incarcerated parents, students in military families, and students who are at risk for school failure and dropout.