This study examines the effect of corporate governance determinants on accounting information disclosure quality among 148 firms listed on the Nigerian Exchange Group (NGX) over 15 years (2010 to 2024). Using panel data regression analysis, the research investigates how board size, board independence, board diversity, audit committee effectiveness, ownership concentration, and CEO duality influence the quality of accounting information disclosure. The study employs a comprehensive disclosure quality index as the dependent variable while controlling for firm size, profitability, growth opportunities, firm age, and liquidity. The findings reveal that board independence, board diversity, and audit committee effectiveness significantly enhance disclosure quality, whereas CEO duality is negatively associated with disclosure transparency. Board size demonstrates a non-linear relationship, and ownership concentration shows mixed effects depending on ownership type. The results remain robust across various econometric specifications, including fixed effects, random effects, and system GMM estimators. These findings contribute to the literature on corporate governance in emerging markets and provide practical implications for regulators, investors, and corporate boards seeking to enhance financial reporting transparency. The study recommends strengthening board independence requirements, promoting gender diversity in boardrooms, enhancing audit committee competencies, and implementing stricter disclosure regulations in the Nigerian context. The research addresses the gap in understanding governance-disclosure dynamics in Sub-Saharan African markets and offers insights for improving corporate governance frameworks in developing economies.