This study investigates the relationship between audit committee financial expertise and audit report lag among listed firms in Nigeria over the period 2010–2025. Drawing on agency theory and resource dependence theory, the paper argues that audit committees composed of financially competent members are better positioned to oversee the financial reporting process, thereby reducing the time elapsed between a firm's fiscal year-end and the date of the external auditor's report. Using an unbalanced panel dataset of 148 firms listed on the Nigerian Exchange Group (NGX), the study employs fixed-effects and random-effects panel regression models alongside the Hausman specification test to select the appropriate estimator. Control variables include firm size, return on assets (ROA), financial leverage, Big 4 auditor affiliation, board independence, industry dummies, and year dummies. The results reveal that audit committee financial expertise exerts a statistically significant negative effect on audit report lag, indicating that firms with more financially expert audit committee members complete their audits faster. Firm size, Big 4 affiliation, and board independence are also associated with shorter audit report lags, while leverage is positively associated with delays. ROA exhibits a negative association with audit report lag. The findings contribute to the corporate governance and auditing literature in an emerging market context and carry important implications for regulators, boards of directors, and investors in Nigeria and comparable economies.