Emotional regulation not only contributes to developmental change, but is itself a developmental process. Emotion regulation strategies, application, and effectiveness also vary across age groups. Interventions to improve emotion regulation must be tailored to the unique needs of children, adults, and older adults. Therefore, understanding its life cycle development is of utmost importance. However, to date, developmental studies have largely focused on specific life stages, and research across different age groups speaks little. This chapter aims to synthesize the available evidence from lifespan perspective moving from childhood through adolescence to adulthood and old age. It reviews key findings on how individuals at different developmental stages have specific needs and limitations related to emotion regulation, and how clinicians might use evidence-based therapy approaches to effectively address these diverse age groups. In childhood, emotion regulation skills are just emerging, and interventions should focus on building foundational abilities such as recognizing emotions and using simple strategies. For adults, interventions can target more complex regulation skills to manage intense emotions and maladaptive patterns. Older adulthood brings changes in cognition, physical health, and social context that require adapting emotion regulation approaches. By aligning interventions with age-related emotional and cognitive changes, clinical therapists can help individuals to adaptively manage their feelings across all stages of life.