Within the East African Community (EAC), corporate accountability (CA) is a relatively novel phenomenon, and human rights discourses underpinning a corporate accountability ethos are evolving but have yet to crystallize into legally binding norms. Besides the EAC partner states and corporate actors, a prominent set of civil society organisations (CSOs) has left a notable imprint on the business and human rights landscape in the region. The chapter explores three CSOs in the EAC partner states of Kenya, Uganda, and Tanzania, delving into their mobilizational strategies, impact on CA practices, and the structural constraints they encounter. I posit that the mobilisation of civil society has notably influenced businesses’ practices, including the embrace of soft law, the organisation of human rights trainings by corporate entities, adjustments to business human rights policies, and measures of redress and remedy to victims of corporate malpractice. While these are significant steps, more robust forms of corporate accountability, such as binding regulations or the criminalization of corporate violence, are still pending. Moreover, such mobilisations have been dominated by “upward accountability” in CSO activities at the expense of “downward” (bottom-up) accountability.