This thesis explores the fundamental tensions between capitalism and sustainability, focusing on the systemic challenges of economic inequality, corporate influence, and resource depletion. It critically engages with key sustainability frameworks, including the Brundtland Report and the concept of planetary boundaries, to assess whether capitalist economies can be restructured to align with long-term environmental and social goals. A comparative analysis of Denmark and the United States provides insight into how different capitalist models address these challenges. Denmark’s coordinated, policy-driven approach contrasts with the United States’ decentralized, market-oriented system, illustrating how governance structures, cultural values, and economic policies shape sustainability outcomes. The findings highlight the need for institutional reforms, stronger regulatory mechanisms, and corporate accountability to reconcile capitalism with sustainability. By integrating theoretical perspectives with empirical analysis, this study contributes to ongoing debates on sustainable capitalism and offers insights into pathways for more equitable and ecologically responsible economic models.