Introduction: An interconnected world is impelling workforce composition towards cultural heterogeneity. Since leadership is a cultural construct, leaders should display those styles that enable them to function effectively in culturally varied conditions. Cultural intelligence could assist leaders in this respect. Purpose: To investigate the role cultural intelligence plays in the leadership style (empowering and directive leadership) and leadership effectiveness domain, so as to aid leader selection and development. Method: A systematic review of the cultural intelligence literature, coupled with content and thematic analysis, allowed for the knowledge to be organised per the concept, definition and truth statement (validated hypotheses) elements of the general body of scientific knowledge framework. Correlation and regression analysis of cross-sectional survey data, from 1140 respondents, were used to assess relationships between leader cultural intelligence, leadership styles (empowering and directive) and leadership effectiveness. Results: Nine concepts associated with, and 24 different definitions of cultural intelligence, were identified. Sixty percent of hypotheses on cultural intelligence have been confirmed as truth statements. The relationship between leader cultural intelligence and empowering leadership demonstrated a large practical effect. This relationship was underpinned primarily by metacognitive and motivational cultural intelligence. The relationship with directive leadership carried a medium practical effect, and was strongest at the motivational and cognitive cultural intelligence levels. The part played by subordinates’ cultural identity in the display of empowering and directive leadership by culturally intelligent leaders was insignificant; rather, leader cultural intelligence was the dominant informant of these leadership styles. Finally, leader cultural intelligence did not impact the relationship between empowering leadership and leadership effectiveness. Although it did negatively affect the directive leadership and leadership effectiveness relationship, the moderation had no practical effect. Conclusions: The concepts associated with cultural intelligence are: accomplishment, culture, expatriates, experience, fit, intelligence, motivation, supervision and training. Cultural intelligence definitions remain mostly based on those of the seminal authors. The majority of truths cover just six themes. Leadership style (empowering and directive) is a function of leader cultural intelligence. Although leader cultural intelligence extends beyond subordinates’ cultural identity in predicting empowering and directive leadership, it does not influence their relationships with leadership effectiveness. / Graduate School of Business Leadership (SBL) / D.B.L.