The chapter explores the critical peace-sustainability nexus as a transformative framework to address the interconnected global crises of armed conflict, environmental degradation, and socio-political instability. It emphasizes the inadequacy of siloed approaches to peacebuilding and sustainability, advocating for integrated solutions that foster positive peace—characterized by social justice, inclusive institutions, and equitable resource distribution—and proactive sustainability practices that regenerate ecosystems and strengthen resilience. As an introductory chapter for a book of the same title, it highlights how peaceful societies are better equipped to invest in environmental stewardship, while healthy ecosystems reduce resource-based conflicts. The chapter also discusses barriers to implementation, including institutional inertia, fragmented funding mechanisms, and the risk of inequitable policies. It calls for transdisciplinary frameworks, adaptive designs, and the empowerment of local communities to bridge the gap between vision and action. By urging the integration of peace and sustainability, the chapter envisions a future where thriving societies coexist with regenerating ecosystems, offering a hopeful counter-narrative to the grim realities of the polycrisis. This work contributes to advancing operational frameworks and practices for achieving peaceful and sustainable futures.