This paper investigates the incorporation of sustainable development within the Portuguese agri-food sector amid global environmental and resource challenges. It underscores the role of the Sustainable Development Goals (SDGs) and environmental, social, and governance (ESG) criteria in steering businesses towards sustainable practices. Through qualitative analysis, in-depth interviews with managers and experts explored sustainable business model adoption, highlighting SMEs’ unique challenges. The study reveals a divergence in sustainability practice maturity, advocating for integration into organizational culture and strategy. It points out SMEs’ reactive stance due to resource constraints and external pressures, contrasting with larger firms’ proactive approaches. The research supports a strategic reevaluation of business models for sustainability, emphasizing innovation, leadership, organizational commitment, and transparent communication. Practical contributions include embedding sustainability into core operations, enhancing competitiveness, fostering sustainable organizational culture, prioritizing employee well-being, and leveraging innovative marketing for sustainability communication. Recognizing its limitations, this study advocates exploring blockchain and AI for transparency, leadership’s role in sustainable models, and the importance of marketing in the agri-food sector for sustainable management. Insights indicate that innovation and strategic partnerships are crucial for enhancing organizational sustainability and achieving the SDGs.