Because of ethnic and cultural violence in Myanmar, approximately a million Rohingya fled to neighboring Bangladesh starting from August 2017, in what the UN has called a “textbook example of ethnic cleansing”. Those arriving in Bangladesh were able to escape decade-long ethnic violence in Myanmar, but the Rohingya’s immediate destination, Cox’s Bazar district is one of the most climate-vulnerable and disaster-prone areas in Bangladesh. Currently, they have been subjected to extreme rainfalls, landslides, and flashfloods. With the COVID-19 pandemic, they continue to face fear and further marginalization in resource-constrained Bangladesh, as well as increased vulnerability due to tropical cyclones, flashfloods, and landslides. The Rohingya in southeast Bangladesh are now at the epicenter of a humanitarian and sustainability crisis. However, their situation is not entirely unique. Millions of displaced, stateless or refugees around the world are facing multi-dimensional crises in various complex geopolitical, and climatic situations. Using the theoretical lens of political ecology and critical development studies, this paper analyzes the sustainability–peace nexus for millions of Rohingya in Myanmar and in Bangladesh. This paper is based on information from various sources, including three ethnographic field visits in recent years, which helped to get local insights into the current sustainability challenges in this humanitarian context. The core arguments of this paper suggest that sustainability–peace nexus will especially be compromised in climate-vulnerable resource-constrained conditions. To overcome this challenge, decolonizing Rohingya solutions would be critical, by engaging the Rohingya in the process of development and meaningful change, which can affect their lives, livelihoods, and wellbeing. Even though this paper has a specific geographical focus, the insights are relevant in parts of the world facing similar social, economic, political, and environmental challenges.