Innovation is often thought of as an outcome. In this chapter, we review the literatures on innovation processes pertaining to the invention, development, and implementation of ideas. In particular, we explore how these processes unfold within firms, across multi-party networks, and within communities. Moreover, we identify four different kinds of complexities associated with innovation processes that we label as evolutionary, relational, temporal, and cultural complexities. While one approach is to manage or control such complexities, we draw attention to literatures that suggest that it is far more productive to harness these complexities for sustaining ongoing innovation. We conclude the chapter by highlighting some areas for future research.