In this chapter, the authors explore leadership and its relation to emotion. While looking at who is a leader, they present the basics around the concept of emotional intelligence, and its huge impact in the last decades. Research findings will be presented to highlight fundamental characteristics of leaders, such as mindfulness, the ability to manage emotions of the self and the others, empathy, as well as social skills, intended as the ability to handle relationships, in group and social settings. Furthermore, they introduce the concept of emotional labour, which consists of a range of work-related emotions, and the four Cs theory that suggests we should appreciate emotions according to context, challenges, communication, and community. Lastly, the authors present models and processes to measure leadership traits, such as performing a social network analysis or a personality test.