Intrastate armed conflict has become the most frequent and deadly form of engagement in the world after the end of the Cold War. The massification of the use of Information and Communication Technologies and the digitization of political activities have turned intrastate conflicts into information-centric conflicts. In this context, cyberspace can be a battlefield as well as a space to conduct peacebuilding activities. Drawing upon literatures in conflict resolution and cybersecurity, this chapter proposes a definition of cyber peacebuilding as an active concept that captures those actions that delegitimize online violence, build capacity within society to peacefully manage online communication, and reduce vulnerability to triggers that may spark online violence. Cyber peacebuilding can also shed light on the relationship between intrastate conflicts and global cyber peace, contributing to raise awareness about cyberthreats in the Global South. The chapter uses the cases of Colombia and South Africa in order to illustrate the challenges and prospects of cyber peacebuilding organized around the four pillars of cyberspace outlined in this volume. Moreover, it argues that cyber peacebuilding in the Global South is an essential element of the emergence of cyber peace as a global public good.