Corporate Social Responsibility (CSR) is now a necessity issue in modern research and business practice, especially in those industries where moral obligations have a direct impact on the overall well-being. This study investigates the effect of industry regulations on the CSR-ethical leadership correlation in Nigeria's pharmaceutical industry. It is supported by stakeholder theory, legitimacy theory, institutional theory, and the capability approach. CSR is the dependent construct that is influenced by the dimensions of sustainability orientation, transparency, integrity, and stakeholder engagement of ethical leadership. Industry regulation is positioned as a moderating variable that has the potential to suppress innovation or encourage pioneering CSR initiatives. The research adopts a secondary design with a systematic literature review supported by peer-reviewed articles, regulatory filings, and sustainability reports. Empirical data are drawn from multinational corporations such as GlaxoSmithKline, Pfizer, and Novartis, and local firms such as Fidson Healthcare and May & Baker Nigeria. Findings indicate that CSR implementation is significantly boosted by ethical leadership, but the profundity and maintenance of such endeavors are highly reliant on regulatory contexts. Multinationals align CSR to global Environmental, Social, and Governance (ESG) norms, while local firms focus on location-specific activities such as subsidized drugs, health literacy programs, and community development initiatives. This study concludes by stating that the transformative potential of CSR in the Nigerian pharmaceutical sector is eroded by weak regulatory enforcement, corruption, and institutional inefficiencies. It contributes to literature by combining leadership and regulatory frameworks in making practical recommendations to policymakers to strengthen governance structures and to business leaders to include sustainability-based CSR initiatives in alignment with international standards as well as domestic healthcare demands.