Chief Executive Officers (CEOs) are essential in driving firm innovation. However, despite existing research on CEO personality characteristics and firm innovation and performance, we know relatively little about how personality characteristics reflecting anticipatory action and strong outcome-oriented components, such as proactiveness, shape firm innovation and performance. We explore the relationship between CEO proactiveness and three facets of organizational innovation, as well as its impact on firm performance. We suggest that CEO proactiveness is manifested in different network-building, problem-solving, and feedback-seeking behaviors with different implications for exploratory innovation, exploitative innovation, and organizational ambidexterity, and that its effect on firm performance is partially mediated by organizational ambidexterity. By examining the influence of this important CEO personality characteristic on key firm strategic choices and performance, we extend research on strategic leadership and firm innovation and performance.