["Corporate Social Responsibility and Environmental Management, EarlyView. ", "\nABSTRACT\nThis study examines the association between corporate social responsibility (CSR) disclosure and firm value in African capital markets, focusing on the divergence between market‐based and accounting‐based value measures, the value relevance of CSR sub‐dimensions (economic, social, environmental), and institutional heterogeneity across four African markets. A balanced panel of 800 firm‐year observations from 80 publicly listed firms across South Africa, Nigeria, Kenya, and Ghana (2015–2024) is analysed using two‐way fixed‐effects panel regression with HC1 heteroskedasticity‐robust standard errors. Two complementary dependent variables, Tobin's Q (market‐based) and Economic Value Added (EVA, accounting‐based), are employed. CSR disclosure is measured using the GRI G3.1 framework, with scores decomposed into economic, social, and environmental sub‐dimensions. CSR disclosure is positively and significantly associated with Tobin's Q (β = 0.003, p < 0.01), implying a 4.8% market‐value premium per standard‐deviation increase in CSR disclosure. However, CSR disclosure is negatively and marginally significantly associated with standardized EVA (β = −0.004, p = 0.053), revealing a market–accounting value gap that is novel in the African CSR literature. The scarcity premium effect on CSR disclosure is greatest in Ghana (β = 0.013, p‐value = 0.003), while the same phenomenon is absent in South Africa after controlling for firm‐level fixed effects, consistent with the concept of institutional quality gradient. This research measures the extent of CSR disclosures and does not consider the quality of CSR initiatives. Using the lagged dependent variable makes CSR non‐significant and shows contemporaneous effects from the stock market. For causal identification, more convincing instruments are needed. CSR disclosure in African markets is associated with measurable market value, supporting the business case for transparent sustainability reporting. Managers need to understand that accounting returns do not wholly account for the added value of CSR initiatives. To the authors' knowledge, this paper offers the first multi‐country African panel study, highlighting the existence of market–accounting value separation and institutional quality gradient on CSR disclosure.\n"]