This study examined the effect of working capital management on the financial performance of listed manufacturing firms in Nigeria. The specific objectives were to determine the impact of accounts receivable, accounts payable, inventory management, and cash conversion cycle on financial performance, measured by return on assets (ROA). The study adopted an ex post facto research design and utilized secondary data obtained from the annual reports of selected manufacturing firms listed on the Nigerian Exchange Group over a specified period. Data collected were analyzed using descriptive statistics, correlation analysis, and multiple regression techniques. The findings revealed that accounts receivable, inventory, and cash conversion cycle have negative and significant effects on financial performance, while accounts payable has a positive and significant effect. This implies that inefficient management of receivables and inventory reduces profitability, whereas effective management of payables enhances firm performance. The study concluded that working capital management plays a crucial role in determining the financial performance of manufacturing firms in Nigeria. It is recommended that firms adopt efficient credit policies, optimize inventory levels, and reduce the cash conversion cycle to improve profitability and liquidity. The study contributes to existing literature by providing empirical evidence on the relationship between working capital management and financial performance in the Nigerian manufacturing sector and offers practical insights for managers, investors, and policymakers.