Corporate Social Responsibility (CSR) has evolved from a peripheral philanthropic activity into a core element of business strategy. Traditionally, businesses were evaluated solely by their capacity to generate profits. However, in the modern era, organizations are increasingly accountable to a wide range of stakeholders—including employees, customers, governments, communities, and shareholders. This transformation is rooted in the recognition that business sustainability is inextricably linked to social responsibility. CSR, often described as corporate citizenship or corporate conscience, refers to the voluntary yet strategic commitment of corporations toward societal development through programs in healthcare, education, rural transformation, environmental protection, and cultural preservation. This study focuses on Reliance Industries Limited (RIL), one of India’s largest and most profitable conglomerates. Using secondary data drawn from annual reports, research articles, and online sources, the study evaluates RIL’s CSR activities between 2010 and 2023. Statistical correlation analysis is applied to examine the relationship between CSR spending and financial performance indicators such as net profit, net revenue, and total assets. Findings reveal that healthcare received the highest proportion of CSR funds (52%), followed by education (22%) and rural transformation (18%), while environmental initiatives accounted for less than 1%. The correlation analysis demonstrates a strong positive relationship between CSR spending and financial performance. The study concludes that CSR not only enhances corporate reputation but also contributes to business sustainability by creating long-term value for stakeholders.