This study examines the effect of governance disclosure on the valuation of listed non-financial firms in Nigeria and tests whether managerial competence moderates this relationship. Using panel data covering 88 listed non-financial firms over the period 2015–2024, governance disclosure is measured through a GRI-based content-analysis index, managerial competence is proxied by the Efficiency-Driven Ability (EDA) approach of Demerjian, Lev and McVay (2012), and firm value is proxied by Tobin’s Q. Fixed Effects panel regression, preferred on the basis of the Hausman specification test, is employed for estimation. The results show that governance disclosure, on its own, exerts a negative and statistically significant effect on firm value, suggesting that disclosure without effective implementation may be perceived by the market as symbolic rather than substantive. Managerial competence, however, has a positive and significant direct effect on firm value and significantly and positively moderates the governance disclosure and firm value relationship, indicating that the value relevance of governance disclosure is conditional on the competence of the managers who design and implement it. The study is anchored on Agency Theory and the Resource-Based View and contributes evidence that governance reporting in emerging markets such as Nigeria only translates into firm value when it is backed by credible managerial capability.

Keywords: Governance Disclosure, Firm Value, Managerial Competence, Corporate Governance, Tobin’s Q, Emerging Markets.