Low mood is the most commonly diagnosed mental health condition affecting adolescents; however, it remains complex to treat due to multi-systemic risk and maintaining factors. Behavioural Activation (BA) is a brief therapy which demonstrates promising treatment outcomes, although limited qualitative accounts exist of how adolescents experience this. This is one of the first studies undertaken in Child and Adolescent Mental Health Services (CAMHS) to explore the perspectives of adolescent’s with low mood who have received BA therapy. Interpretative phenomenological analysis was conducted from one-to-one interviews with nine adolescents who received BA, generating an idiographic account of their experiences. Three superordinate themes emerged: how the format of BA can promote the integration of coping skills into one’s life; how interpersonal connections and therapeutic relationships may improve intervention outcomes; and how BA principles could be internalised as part of a young person’s day-to-day life. Participants valued the structure and flexibility of the manualised approach, forming an alliance with the therapist, and enhancing interpersonal relationships. This study details how BA can enhance resiliency skills for adolescents experiencing low mood and illustrates some of the change process at inter and intrapersonal levels, which should guide further youth-led research.