Depression is a prevalent mental health disorder among youth, with rising rates and significant comorbidities. It severely impacts social life, school attendance, and family relations. Furthermore, depression is associated with peer difficulties, suicidality, increased risk of substance abuse, and a reduced quality of life. Cognitive behavioral therapy (CBT) is a well-established and effective treatment for depression in youth. Core principles in CBT for depression is to address thoughts and behaviors that perpetuate depressive symptoms. The current chapter presents key principles of CBT for depression in youth using examples, strategies for overcoming challenges, illustrations, and sample dialogues between youth and therapist. It offers valuable knowledge and resources for practitioners working with depressed youth, providing useful tools for clinical practice.