Sustainability has become a strategic imperative for organizations seeking to balance economic performance with social responsibility and environmental stewardship. Although sustainability integration has received considerable attention in contemporary management research, limited understanding exists regarding the internal organizational factors that facilitate the effective incorporation of sustainability principles into business operations. Among these factors, corporate spirituality has emerged as a promising yet underexplored construct. Drawing upon Person–Organization Fit Theory, this study examines the influence of corporate spirituality on Corporate Sustainability among listed and non-listed companies in Sri Lanka. Corporate spirituality is conceptualized through the dimensions of compassion, inner life, joy at work, mindfulness, social connectedness, and values alignment, reflecting the extent to which spiritual values are embedded within organizational culture and practices. Corporate Sustainability is assessed through economic, environmental, and social dimensions, representing the holistic incorporation of sustainability principles into organizational strategies and operations. The findings indicate that organizations characterized by stronger spirituality-oriented practices demonstrate greater integration of sustainability considerations into their business activities. The results support the proposition that alignment between employee values and organizational values encourages behaviors and practices that advance organizational objectives. By extending the spirituality–sustainability discourse from workplace spirituality to corporate spirituality, this study contributes to the growing body of knowledge on sustainable organizational development and highlights the importance of cultivating values-based organizational cultures to support long-term sustainability goals and stakeholder value creation. The study further provides empirical evidence from a developing-country context and offers practical insights for organizations seeking to strengthen sustainability integration through values-driven management practices.