With the transition from the industrial age to the digital age, a notable phenomenon is the adoption of the chief digital officer—a senior executive position dedicated to digital issues—in large firms. To explore this phenomenon, we conduct a large-scale, empirical study of the emergence of the chief digital officer position, potential variations of this role, and the conditions under which firms choose to have this position. Our exploratory analysis of all firms in the S&P 1500 index between 2000 and 2018 offers unique insights. In descriptive terms, we find that chief digital officers did not appear until 2003 and their prevalence has increased notably since 2010. In addition, an analysis of these executives' titles and role descriptions alludes to two conceptually different types of chief digital officers: generalists and domain specialists. In prescriptive terms, we reveal several factors related to firms’ performance, strategic leadership, task demands, task environments, and mimicry behavior that influence the likelihood of chief digital officer presence. The combined empirical insights call for nuanced theoretical explanations of the chief digital officer phenomenon. Our study informs research on chief digital officers and functional executives in general. More generally, it provides a window into the larger issue of the microfoundations of digital transformation and strategic change in large firms, and it points to new strategy actors and practices.