The importance of involving citizens in the early stages of public sector innovation and bottom‐up governance arrangements for collaboration has been proposed in a number of theoretical papers. However, to date, few empirical studies are evident in the literature. To deepen our understanding of collaborative public sector innovation, our exploratory article analyses: (i) the actors of collaboration, (ii) collaboration across the innovation stages, (iii) the perceived aspects of collaboration for innovative outcomes, and (iv) the governance of collaboration. Our analysis covers 99 innovations from Italy, Japan, and Turkey. We reveal that collaboration still largely occurs within the bureaucracy of public sector organizations. Attempts to include civic and private sectors are evident, depending on the country context. Further, we uncover that a mutual understanding and shared goals are crucial for success, which is accomplished through top‐down governance as opposed to self‐governed bottom‐up networks.