This paper explores the relationship between internationalization and corporate social responsibility (CSR) communication in Russian firms. Our baseline argument is that internationalization positively affects CSR reporting, as it is expected to enhance the legitimacy of Russian firms abroad. We examine the role of state ownership, and Commonwealth of Independent States (CIS) vs. non-CIS location, as two boundary conditions on the relationship between internationalization and CSR reporting. We test our hypotheses on panel data of 223 large Russian firms for the period 2012–2017, collected from company annual reports, databases, and official company websites. Our data include financial and non-financial indicators, and firm-level organizational characteristics. The results reveal the context specificity of CSR reporting. We find that state ownership moderates the relationship between internationalization and CSR reporting in CIS and non-CIS markets differently, and the positive effect is stronger for non-CIS locations. Our study goes beyond the traditional approach, treating CSR reporting as a unidimensional construct. We show that the effect of internationalization, both direct and moderated, differs for the different types of CSR activity.