As scholars continue in their quest to find factors that are related to leadership style, leadership behavior, and leadership effectiveness, we observe a revival in interest with regards to emotionality. As recent research suggests the rising importance of emotional reasoning over intelligence in leadership, the complex phenomena surrounding emotions in the workplace spur studies with contradictory, albeit important, results. The purpose of this review is to unify and integrate research conducted in the past decade that links emotionality with leadership style, behavior, and effectiveness. In conducting this review, we observed four running themes: emotional competencies of leaders (e.g. emotional expressiveness and emotional intelligence), stress in leadership, contagion of positive and negative affect, and the effects of leaders' emotions on outcomes like burnout and performance. On top of taking stock of studies that theoretically and empirically test these relationships, we also summarize literature on potential mechanisms that link emotionality with leadership and highlight directions for future research.