This chapter describes the way in which functional analytic psychotherapy (FAP) provides a behaviorally-informed framework for cultivating transformative therapeutic relationships. Grounded in contextual behavioral science, FAP emphasizes the “here and now” through contingent therapist responses to in-session client behaviors, referred to as clinically relevant behaviors (CRBs). These behaviors, categorized as CRB1s (problematic) and CRB2s (improvements), mirror clients’ patterns in daily life, offering unique opportunities for intervention. FAP’s five rules—awareness, evocation, reinforcement, impact assessment, and generalization—equip therapists with strategies to foster trust, intimacy, and meaningful change. By focusing on relational process over content and encouraging authentic expression, FAP creates a therapeutic environment where vulnerability and connection are not only evoked but also reinforced. Empirical evidence supports FAP’s effectiveness in enhancing interpersonal functioning, reducing distress, and promoting social connectedness. As the field continues to evolve, FAP stands out as a unique and valuable approach for deepening the therapeutic relationship and enhancing outcomes across diverse populations and clinical contexts.