Our research focuses on the contextualized agency of Southern civil society organizations (CSOs) shaping their advocacy roles. We thereby seek to relate to the widespread aim of helping to make sure that development is owned by people and organizations ‘on the ground’. A long-term goal in the field of international development is to create conditions where responsibilities and leadership increasingly lie with Southern CSOs (Banks et al., 2015; Miller-Dawkins, 2017; Netherlands Ministry of Foreign Affairs, 2018; Goodman, 2016; Forsch, 2018). If Southern CSOs are to do more leading, their contexts, understandings, and ambitions must move more to the centre of programmes and collaborations. Our research can help donors and Northern CSOs to establish what that would mean in practice when it comes to fundamental questions regard-ing whom to work with, what to work for, how to collaborate, and what this implies for various actors’ roles.