Management of complex service innovations, such as integrated health and social care organizations, is known to be demanding. In this chapter, co-leadership will be elaborated as one approach to address the challenges that arise from organizational complexity. This is preceded by a short historical background about how the interpretation of leadership has changed over time, from focusing on the leaders’ personality to envisioning leadership as a function or activity that numerous persons in an organization can have and share at the same time. This chapter is based on literature in the scientific field of integrated care and leadership research and the empirical findings discussed in emanate from a research project.