Corporate environmental responsibility (CER) has become a crucial aspect of business strategy as firms seek to balance sustainability with profitability. This study investigates the impact of CER on the financial performance of Nigerian manufacturing firms, focusing on key financial indicators such as return on assets, profitability, and market valuation. A quantitative approach is employed, utilizing secondary data from financial reports, sustainability disclosures, and regulatory filings of selected firms over a defined period. The results revealed R2 = 0.775; Adj R2 = 0.728 and P- Value of 0.0000 which indicates a positive correlation between proactive environmental initiatives and financial performance, suggesting that firms adopting sustainable practices benefit from enhanced brand reputation, cost efficiency, and regulatory compliance. However, challenges such as high implementation costs and weak enforcement mechanisms limit broader adoption. The study concludes that corporate environmental responsibility significantly influences financial performance in the Nigerian manufacturing sector by fostering a culture of environmental responsibility, promoting transparency, and strengthening regulatory support, Nigerian manufacturing firms can enhance their sustainability performance while maintaining a competitive edge in the industry. The study recommended that Nigerian manufacturing firms should integrate environmental sustainability into their core business strategies to enhance reputation, build consumer trust, and improve financial performance. Management should prioritize sustainability as a long-term business goal rather than a regulatory obligation.