This cumulative dissertation investigates the role and implications of top managers in firms. By building on two influential contemporary phenomena – internationalization and digitalization – and by examining top managers from a multitude of conceptional and methodological angles, the dissertation provides novel insights to upper echelons research. The first study examines the association between top management team (TMT) internationalization and firm innovativeness and argues that the accumulation of international knowledge and resources in the TMT benefits firm innovativeness. The second study analyzes the association between CEO internationalization and firms’ strategic risk-taking, paying particular attention to various governance mechanisms that may influence this relationship. The third study explores the role and facilitating actions of top managers in response to the digital transformation. Overall, this dissertation contributes toward a more fine-grained understanding of top managers and their individual characteristics. Given the contemporary relevance of the topics under consideration, the presented findings are of significant value for both theorists and practitioners.:Chapter 1: Introduction 1.1 Scope of the dissertation and research gaps 1.2 Theoretical foundation 1.3 Empirical foundation 1.4 Research purpose and scientific contribution Chapter 2: Research article 1 2.1 Introduction 2.2 Theory and hypotheses 2.3 Methodology 2.4 Results 2.5 Discussion and conclusions 2.6 Limitations and future research Chapter 3: Research article 2 3.1 Introduction 3.2 Theory and hypotheses 3.3 Methodology 3.4 Results 3.5 Discussion and conclusion 3.6 Limitations and future research Chapter 4: Research article 3 4.1 Introduction 4.2 Theoretical background 4.3 Data and method 4.4 Findings 4.5 Discussion References