Two decades after its endorsement at the 2005 UN World Summit, the Responsibility to Protect (R2P) remains significant in Southeast Asia, especially considering the 2017 Rohingya refugee crisis and the 2021 military coup in Myanmar. Analyzing the approaches of key actors—states, civil society, and regional organizations in Southeast Asia—reveals that civil society has emerged as the most proactive actor in promoting R2P. Civil society organizations (CSOs) have developed transnational networks and promoted “atrocity prevention” rather than military intervention, which is often perceived as R2P’s core component. Conversely, although many Southeast Asian states have partially accepted R2P, they have not actively promoted its implementation. Similarly, ASEAN has evolved, shifting from non-interference to “non-indifference” in response to the crises in Myanmar, while avoiding direct reference to R2P. While neither Southeast Asian states nor ASEAN have actively promoted R2P, their reactions to related issues suggest a growing recognition of the need for more decisive action.