Emotion regulation is important for optimal relationship functioning because it can help avoid conflict and create smoother, more enjoyable interactions. However, there are many ways to regulate emotion, and each strategy has a unique profile of consequences, with some emotion regulation strategies being more beneficial than others. Our goal in this chapter is to provide a framework for thinking about and studying the link between emotion regulation and close relationships. First, we provide a broad overview of emotion and emotion regulation, highlighting the most important intrapersonal consequences that are relevant to relationship functioning as well as the direct interpersonal consequences. Then we outline some important emerging themes in the emotion regulation and close relationship literature, including (1) moving beyond the individual regulating his or her own emotions, (2) exploring underlying mechanisms, (3) isolating boundary conditions, and (4) examining the role of close relationships in shaping emotion regulation efforts. Finally, we discuss the broader implications of the existing research on emotion regulation and relationships, and propose some new and promising directions for future research. Throughout the chapter, we show that emotion regulation both influences and is influenced by close relationships.